The Calorie Balance Thread

[dashforce]

I would like to start a thread to examine the calorie balance "hypothesis." I hope to include only studies that were tightly controlled, as evidence has shown that self-reported intake is highly inaccurate, even in trained individuals (I also hope to start a thread discussing this). Therefore, I wish to completely avoid studies that use self-reported data.

I expect that the majority of these studies will come form closely monitored metabolic wards, and I'd also like to include some that utilized doubly labeled water, as these seem some of the most reliable studies as far as actual intake is concerned. As these studies are very expensive, I will not be surprised if there are not many available. However, I feel that the data they contain may be significantly more valuable than studies that utilize self-reported data.

The major point I wish to examine will be net calorie balance vs weight (ie, the calorie balance "hypothesis"). However, bonus points will be awarded for studies that meet the above criteria and also compare *isonitrogenous* low and high carbohydrate diets, especially if body composition (and not just weight) is analyzed.

I'll start.

Just because this is interesting:
<div class='quotetop'>QUOTE </div><div class='quotemain'>Am J Clin Nutr. 1995 Oct;62(4):735-9. Links
Energy metabolism in weight-stable postobese individuals.

Larson DE, Ferraro RT, Robertson DS, Ravussin E.
Clinical Diabetes and Nutrition Section, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Phoenix, AZ, USA.
A low metabolic rate for a given body size and body composition and a low ratio of fat to carbohydrate oxidation predict body weight gain. Such metabolic traits could also explain, in part, the propensity of previously obese (postobese) individuals to regain weight after dieting. We studied 11 postobese volunteers (4 males, 7 females; aged 43 +/- 13 y, weighing 80.6 +/- 10.2 kg, with 30 +/- 7% body fat; x +/- SD) who lost 57 +/- 38 kg (23-139 kg) over 14 +/- 12 mo (6-48 mo) on various diet programs and had maintained this weight loss for > or = 2 mo (2-72 mo; 21 +/- 27 mo). After > or = 2 d of a weight-maintenance diet on a metabolic ward, 24-h energy expenditure and ratio of fat to carbohydrate oxidation were measured in a respiratory chamber. Compared with a control group (n = 110) with similar physical characteristics (aged 43 +/- 14 y, weighing 79.5 +/- 11.4 kg, with 30 +/- 12% body fat), [sequence: see text] postobese individuals had similar energy expenditures adjusted for fat-free mass, fat mass, age, and sex, but significantly higher respiratory quotients over 24 h (0.883 +/- 0.026 compared with 0.863 +/- 0.024, P < 0.01) and during sleep, 10 h after the last meal (0.894 +/- 0.063 compared with 0.845 +/- 0.055). These results suggest that postobese individuals have low rates of fat oxidation that may explain their propensity to regain weight.(ABSTRACT TRUNCATED AT 250 WORDS)
PMID: 7572701 [PubMed - indexed for MEDLINE]</div>


This one (FFT) might be interesting discussion -- less than half the carbs, but an appropriate weight loss: deficit ratio (whereas a low CHO enthusiast might expect a significant weight loss: deficit ratio for the lower CHO diet).
<div class='quotetop'>QUOTE </div><div class='quotemain'>Am J Clin Nutr. 1992 Oct;56(4):636-40. Links
Body composition, nitrogen metabolism, and energy utilization with feeding of mildly restricted (4.2 MJ/d) and severely restricted (2.1 MJ/d) isonitrogenous diets.

Stanko RT, Tietze DL, Arch JE.
Clinical Nutrition Unit, Montefiore University Hospital, Pittsburgh, PA 15213.
To determine the effects on weight loss of feeding isonitrogenous diets in mildly restricted (4.2 MJ/d) and severely restricted (2.1 MJ/d) amounts, we measured body composition, weight loss-energy deficit ratio, and nitrogen metabolism in 14 obese women housed in a metabolic ward consuming hypoenergetic diets for 21 d. Subjects consumed either a 4.2-MJ/d diet (50 g protein, 175 g carbohydrate) or a 2.1-MJ/d diet (50 g protein, 75 g carbohydrate). Body composition and leucine oxidation and turnover were determined before and after weight loss. Energy deficit was calculated from resting metabolic rates. Subjects fed the 2.1-MJ/d diet showed a greater weight loss (6.1 +/- 0.5 vs 4.5 +/- 0.5 kg; mean +/- SE, P less than 0.05) and fat loss (3.9 +/- 0.3 vs 3.0 +/- 0.3 kg, P less than 0.05). Weight loss-energy deficit ratio was the same with both diets. Nitrogen balance and leucine oxidation and turnover were similar in both groups. We conclude that with feeding of isonitrogenous hypoenergetic diets, severe restriction of energy content (2.1 MJ/d, 75 g carbohydrate) will enhance weight and fat loss without increasing nitrogen loss compared with mild restriction of energy (4.2 MJ/d).
PMID: 1414962 [PubMed - indexed for MEDLINE]</div>


I don't know what to make of this one, as it involves a supplement outside of normal dietary intake (FFT):
<div class='quotetop'>QUOTE </div><div class='quotemain'>Am J Clin Nutr. 1992 Oct;56(4):630-5. Links
Body composition, energy utilization, and nitrogen metabolism with a 4.25-MJ/d low-energy diet supplemented with pyruvate.

Stanko RT, Tietze DL, Arch JE.
Clinical Nutrition Unit, Montefiore University Hospital, Pittsburgh, PA 15213.
We measured body composition, energy deficit, and nitrogen metabolism in 14 obese women housed in a metabolic ward, who consumed a 4.25-MJ/d liquid diet (68% carbohydrate, 22% protein) for 21 d with or without pyruvate (PY; n = 7) partially, isoenergetically substituted for glucose (placebo; n = 7). Body composition and leucine oxidation and turnover were determined before and after weight loss. Energy deficit was calculated from resting metabolic rates. Subjects fed pyruvate showed a greater weight loss (PY = 5.9 +/- 0.7 kg, placebo = 4.3 +/- 0.3 kg, P less than 0.05), fat loss (PY = 4.0 +/- 0.5 kg, placebo = 2.7 +/- 0.2 kg, P less than 0.05), kg wt loss/4.25-MJ deficit (PY = 0.22 +/- 0.01 kg, placebo = 0.17 +/- 0.01 kg, P less than 0.05, and kg fat loss/4.25-MJ deficit (PY = 0.15 +/- 0.01 kg, placebo = 0.11 +/- 0.01 kg, P less than 0.05). Nitrogen balance (urine and stool) and leucine oxidation and turnover were similar in both groups. We conclude that the dietary modification whereby the three-carbon compound pyruvate is isoenergetically substituted for the six-carbon compound glucose in a 4.25-MJ/d, low-energy diet will increase fat and weight loss.
PMID: 1414961 [PubMed - indexed for MEDLINE]</div>


I'll have to see if I can't get the FT on this one to see if weight loss was measured:
<div class='quotetop'>QUOTE </div><div class='quotemain'>Metabolism. 1992 Apr;41(4):406-14. Links
Protein sparing during treatment of obesity: ketogenic versus nonketogenic very low calorie diet.

Vazquez JA, Adibi SA.
Department of Medicine, Montefiore University Hospital, Pittsburgh, PA 15213.
Although it is generally agreed that both ketogenic and nonketogenic very low calorie diets promote weight reduction, there is no consensus on a preference of one diet over the other in regard to protein sparing. In the present study, we compared the effects of isocaloric (600 kcal/d) and isonitrogenous (8 g nitrogen/d) ketogenic (low carbohydrate) and nonketogenic diets on parameters of protein and amino acid metabolism, in 16 morbidly obese women maintained on these diets for 4 weeks while confined to a metabolic ward. Cumulative urinary nitrogen excretion (g/4 wk) was significantly (P less than .01) greater (248 +/- 6 v 207 +/- 12, mean +/- SEM, n = 8), and cumulative nitrogen balance significantly (P less than .02) more negative (-50.4 +/- 4.4 v -18.8 +/- 5.7), during treatment with the ketogenic than with the nonketogenic diet. Plasma leucine concentration (mumol/L) was significantly higher (P less than .05) during treatment with the ketogenic than with the nonketogenic diet at day 14 (210 +/- 17 v 150 +/- 8), but not at day 28 (174 +/- 9 v 148 +/- 8). Whole-body rates of leucine oxidation (mmol/h) were significantly higher (P less than .05) during treatment with the ketogenic than with the nonketogenic diet at day 14 (1.29 +/- 0.20 v 0.92 +/- 0.10) and at day 28 (1.00 +/- 0.16 v 0.75 +/- 0.10). Conversely, proteolysis, as measured by leucine turnover rate and urinary excretion of 3-methylhistidine, was not significantly different between the diets.(ABSTRACT TRUNCATED AT 250 WORDS)
PMID: 1556948 [PubMed - indexed for MEDLINE]</div>


Possibly due to high bodily stores of energy reserves?
<div class='quotetop'>QUOTE </div><div class='quotemain'>Am J Clin Nutr. 1989 Jul;50(1):41-5. Links
Weight loss in 108 obese women on a diet supplying 800 kcal/d for 21 d.

Webster JD, Garrow JS.
Nutrition Research Group, Clinical Research Centre, Harrow, UK.
A series of 108 obese women were studied for 21 d in a metabolic ward on a diet supplying 800 kcal/d (3.4 MJ/d), with 4.5 g protein nitrogen, 40% energy from fat, and 46% from carbohydrate. The average total weight loss was 5.0 kg. During the second and third week on the diet the rate of weight loss was 211 +/- 77 g/d (mean +/- SD) and individual values were well predicted by admission resting metabolic rate (RMR) (r = 0.66, p less than 0.0001). The calculated energy density of the weight lost in this phase was 7000 kcal/kg (29.3 MJ/kg). However, the weight loss in the first week had a labile component of 815 +/- 1202 g, which was not well predicted by RMR (r = 0.20, p less than 0.05). The effect of this labile component was to obscure the overall rate of weight loss so some of the patients did not show net weight loss until day 13 of the diet, although they were in negative energy balance.
PMID: 2750694 [PubMed - indexed for MEDLINE]</div>

<div class='quotetop'>QUOTE </div><div class='quotemain'>Lancet. 1989 Jun 24;1(8652):1429-31.Links
Effects on weight and metabolic rate of obese women of a 3.4 MJ (800 kcal) diet.

Garrow JS, Webster JD.
Rank Department of Human Nutrition, St Bartholomew's Hospital Medical College, London.
103 obese women (mean [SD] Quetelet's index [weight/height2] 38 [8] kg/m2) were admitted to a metabolic ward and were kept strictly to a diet providing 3.4 MJ (800 kcal) daily for 3 weeks. Body weight was measured daily and fasting resting metabolic rate (RMR) on days 1, 7, and 21. Both weight and RMR fell more rapidly in the first week than later. The thermic effect of feeding fell immediately on the lower energy intake, and there was an adaptive reduction of about 6% in RMR in week 1. After 3 weeks, the average weight loss was 4.9 (1.2) kg (about 5% of initial weight) and the average fall in RMR 8.8%. If after substantial weight loss a woman eats just enough to maintain energy balance the adaptive reduction in metabolic rate is restored to normal, and the thermic effect of feeding is restored in proportion to the new energy intake, but total energy requirements remain less than in the obese state to the extent that fat-free mass has been reduced. Thus, an obese woman who reduces weight by 30% over a year will thereafter have requirements for weight maintenance which are reduced by about 15%.
PMID: 2567437 [PubMed - indexed for MEDLINE]</div>


<div class='quotetop'>QUOTE </div><div class='quotemain'>Am J Clin Nutr. 1987 Oct;46(4):622-30. Links
Effects of exercise and food restriction on body composition and metabolic rate in obese women.

Hill JO, Sparling PB, Shields TW, Heller PA.
Clinical Nutrition Research Unit, Vanderbilt University School of Medicine, Nashville, TN 37232.
Obese women (140-180% of ideal body weight) were studied on a metabolic ward during 1 wk of maintenance feeding, followed by 5 wk of 800 kcal/d (liquid formula diet). Five subjects participated in a supervised program of daily aerobic exercise and three subjects remained sedentary. Total weight loss was not different between exercising and nonexercising subjects but significantly more of the weight loss came from fat and less from fat-free mass in the exercising subjects. Resting metabolic rate (RMR) declined similarly in both groups (approximately 20%), even though exercising subjects were in greater negative energy balance due to the added energy cost of exercise. In summary, results from this controlled inpatient study indicate that exercise is beneficial when coupled with food restriction because it favors loss of body fat and preserves fat-free mass.
PMID: 3661479 [PubMed - indexed for MEDLINE]</div>


<div class='quotetop'>QUOTE </div><div class='quotemain'>Diabetes. 1986 Feb;35(2):155-64.Links
Metabolic consequences of very-low-calorie diet therapy in obese non-insulin-dependent diabetic and nondiabetic subjects.

Henry RR, Wiest-Kent TA, Scheaffer L, Kolterman OG, Olefsky JM.
To determine the effects of very-low-calorie diets on the metabolic abnormalities of diabetes and obesity, we have studied 10 obese, non-insulin-dependent diabetic (NIDDM) and 5 obese, nondiabetic subjects for 36 days on a metabolic ward during consumption of a liquid diet of 300 kcal/day with 30 g of protein. Rapid improvement occurred in the glycemic indices of the diabetic subjects, with mean (+/- SEM) fasting plasma glucose falling from 291 +/- 21 to 95 +/- 6 mg/dl (P less than 0.001) and total glycosylated hemoglobin from 13.1 +/- 0.7% to 8.8 +/- 0.3% (P less than 0.001) (normal reference range 5.5-8.5%). Lipid elevations were normalized with plasma triglycerides reduced to less than 100 mg/dl and total plasma cholesterol to less than 150 mg/dl in both groups. Hormonal and substrate responses were also comparable between groups with reductions in insulin and triiodothyronine and moderate elevations in blood and urinary ketoacid levels without a corresponding rise in free fatty acids. Electrolyte balance for sodium, potassium, calcium, and phosphorus was initially negative but approached equilibrium by completion of the study. Magnesium, in contrast, remained in positive balance in both groups throughout. Total nitrogen loss varied widely among all subjects, ranging from 70 to 367 g, and showed a strong positive correlation with initial lean body mass (N = 0.83, P less than 0.001) and total weight loss (N = 0.87, P less than 0.001). The nondiabetic group, which had a significantly greater initial body weight and lean body mass than the diabetic group, also had a significantly greater weight loss of 450 +/- 31 g/day compared with 308 +/- 19 g/day (P less than 0.01) in the diabetic subjects. The composition of the weight lost at completion was similar in both groups and ranged from 21.6% to 31.3% water, 3.9% to 7.8% protein, and 60.9% to 74.5% fat. The contribution of both water and protein progressively decreased and fat increased, resulting in unchanged caloric requirements during the diet. This study demonstrates that short-term treatment with a very-low-calorie diet in both obese diabetic and nondiabetic subjects results in: safe and effective weight loss associated with the normalization of elevated glucose and lipid levels, a large individual variability in total nitrogen loss determined principally by the initial lean body mass, and progressive increments in the contribution of fat to weight loss with stable caloric requirements and no evidence of a hypometabolic response.
PMID: 3510922 [PubMed - indexed for MEDLINE]</div>


If my math is correct, this study shows greater weight loss than expected if one is using the ~3600 kcal / lb rule. However, only 59% of that was fat.
<div class='quotetop'>QUOTE </div><div class='quotemain'>Am J Clin Nutr. 1984 Sep;40(3):611-22. Links
Variability in body protein loss during protracted, severe caloric restriction: role of triiodothyronine and other possible determinants.

Yang MU, van Itallie TB.
Six morbidly obese subjects were maintained in a metabolic ward for 64 days on liquid diets providing 600 to 800 kcal/day. Three received protein at a level of 1.5 g/kg desirable weight per day. The other three were given an identical diet in which half the protein was replaced by carbohydrate. Because there were no significant differences in either mean protein or mean fat losses between the two groups, the data on all six subjects were combined. Over the 64 days, the mean weight loss (+/- SEM) of the subjects per 1000 kcal deficit was 174.3 +/- 25.5 g. The composition of this weight loss was 36.0% water, 58.9% fat, and 5.1% protein. Although the rate of fat loss was relatively constant throughout the study, wide interindividual variations in cumulative protein (nitrogen) deficit were observed. Total nitrogen losses per subject ranged from 90.5 to 278.7 g. Cumulative nitrogen loss during the first 16 days tended to correlate negatively with initial mean fat cell size and positively with initial lean body mass. Most notable was the strong negative correlation between the size of the decrease in serum triiodothyronine over the 64-day study and the magnitude of the concurrent cumulative N deficit. During severe caloric restriction, one's ability to decrease circulating serum triiodothyronine levels may be critical to achievement of an adaptational decrease in body protein loss.
PMID: 6383009 [PubMed - indexed for MEDLINE]</div>


<div class='quotetop'>QUOTE </div><div class='quotemain'>Postgrad Med J. 1984;60 Suppl 3:66-73.Links
Nitrogen balance studies during modified fasting.

Wechsler JG, Wenzel H, Swobodnik W, Ditschuneit HH, Ditschuneit H.
Protein or nitrogen depletion may be harmful and deleterious as reports of deaths in obese patients fed by liquid protein diets have shown. The aim of our studies was to determine the protein losses (by urinary nitrogen losses) during treatment of obesity with modified fasting over four weeks under inpatient conditions. Sixty-one patients were treated in our metabolic ward with modified fasting randomized into four groups. The daily diet consisted of 33-50 g protein/day, 1-10 g fat/day and 25-45 g carbohydrates/day thus providing 240 to 450 kcal/day or 1.0 to 1.9 MJ. The mean weight losses ranged between 11.0 +/- 0.7 kg and 13.9 +/- 0.9 kg in 28 days. The acceptability and compliance of the four applied diets were excellent and no severe side effects could be observed. The nitrogen balances could be equilibrated from the third week on. The composition of weight lost during modified fasting was as follows. The percentage of body protein ranged between 3% and 16% and the percentage of adipose tissue between 63% and 79% of the total weight loss. Therefore modified fasting represents a very effective and safe therapy of massive obesity.
PMID: 6514657 [PubMed - indexed for MEDLINE]</div>

[dashforce]

<div class='quotetop'>QUOTE </div><div class='quotemain'>Int J Obes. 1983;7(4):345-52.Links
A metabolic ward study of a high protein, very-low-energy diet.

Wilson JH, Lamberts SW, Swart GR.
Seven obese women were placed on a liquid formula diet providing 560 kcal (2.4 MJ) and 70 g protein daily and studied under metabolic ward conditions for four weeks. The diet was well tolerated and hunger sensations were minimal. Mean weight loss was 10.47 kg for the four weeks. A positive nitrogen balance was achieved within two weeks in most patients, but despite this serum prealbumin levels fell as did the excretion of 3-methylhistidine in the urine. Plasma beta-hydroxybutyrate and urate levels rose during the first two weeks but remained constant thereafter. The characteristic decrease in plasma triiodothyronine levels and increase in reverse triiodothyronine levels seen with fasting and other very-low-calorie diets were also observed with this diet. Potassium losses were minimal and no changes in electrocardiograms were seen. This diet would appear to be an acceptable, effective and safe means of achieving rapid weight loss in obesity.
PMID: 6629642 [PubMed - indexed for MEDLINE]</div>


Might should add this one to B's exercise paradox thread:
<div class='quotetop'>QUOTE </div><div class='quotemain'>Int J Obes. 1981;5(1):25-32.Links
The effect of addition of exercise to a regime of dietary restriction on weight loss, nitrogen balance, resting metabolic rate and spontaneous physical activity in three obese women in a metabolic ward.

Warwick PM, Garrow JS.
Three obese women were studied for periods of 12-13 weeks while on a constant reducing diet (800 kcal/day) in a metabolic ward. Body weight and nitrogen balance were measured throughout the study and patients kept continuous diary card records of their physical activity. Fasting resting metabolic (BMR) was measured twice weekly using a ventilated hood apparatus. Each patient acted as her own control by alternatively exercising (2 h/d on a bicycle ergometer) or not exercising for consecutive 3-4 week periods. Rate of weight loss was not increased by this level of exercise over the 3-4 week periods. This surprising result could not be explained by a decreased nitrogen loss since nitrogen balance was not significantly affected by the exercise, not could it be explained by a compensatory decrease in subsequent energy expenditure since BMR and spontaneous activity was not measurably affected by the exercise. However, since exercise increases muscle glycogen stores it may have been this effect which negated the expected increase in weight loss during ther exercise programme.
PMID: 7216603 [PubMed - indexed for MEDLINE]</div>

Perhaps this one too:
<div class='quotetop'>QUOTE </div><div class='quotemain'>Int J Obes. 1978;2(4):441-7.Links
Factors determining weight loss in obese patients in a metabolic ward.

Garrow JS, Durrant ML, Mann S, Stalley SF, Warwick PM.
A metabolic unit is described in which it is possible to make controlled measurements of energy balance in patients with various types and degrees of obesity. Thirty-seven obese women were studied for three consecutive one-week periods on a diet which provided an average of 3.4MJ (800 kcal) daily, and some also undertook an exercise programme involving the expenditure of 850--1275 kJ (200--300 kcal) extra per day. The distribution of energy intake was varied from week to week, and within the day (nibbling and gorging), but neither these variations in dietary pattern nor the exercise programme significantly affected the total weight loss over the three-week study period. Very large variations were observed between individuals. Total weight loss over the three-week study period ranged from 1.6 to 9.8 kg. The best predictor of weight loss in a patient on a strictly controlled diet is the resting metabolic rate. The previous diet also affects weight loss: patients who had been keeping to a reducing diet before admission lost less weight, especially in the first week, than those who had not been dieting immediately before admission to hospital.
PMID: 744682 [PubMed - indexed for MEDLINE]</div>

Too short of a duration to indicate much, but... (FFT)
<div class='quotetop'>QUOTE </div><div class='quotemain'>Am J Clin Nutr. 1977 Feb;30(2):160-70. Links
Effect of diet composition on metabolic adaptations to hypocaloric nutrition: comparison of high carbohydrate and high fat isocaloric diets.

Lewis SB, Wallin JD, Kane JP, Gerich JE.
The metabolic consequences of two hypocaloric diets were assessed in 10 obese men. The study, performed on a metabolic ward, compared the response of these men to two cholesterol-free liquid formula diets of differing composition (10 kcal/kg per day, 70% carbohydrate, 20% protein, 10% fat versus 70% fat, 20% protein, 10% carbohydrate) but identical in calories. These were administered for 14 days in a random order and each diet was preceded by a 7-day control weight maintenance diet (30 kcal/kg per day, 40% carbohydrate, 20% protein, 40% fat). The low calorie diets were well tolerated by the men and effected similar losses of nonaqueous body weight. Fasting glucose and insulin decreased significantly in these men after they ingested either weight loss diet for 14 days, but the change in each parameter was greater for high fat as compared to high carbohydrate (15% versus 7% and 67% versus 35%, respectively, P less than 0.01). In contrast, fasting glucagon concentration decreased in these subjects to a greater extent in response to the high carbohydrate diet (35% versus 16%, P less than 0.01). This adaptive response thus resulted in a 50% fall in insulin:glucagon molar ratio for high fat and no change for high carbohydrate weight loss. Despite these hormonal alterations no change in glucose tolerance was observed. Fasting serum triglyceride and cholesterol levels declined in these subjects to a greater extent following the high fat compared to the high carbohydrate regimen (45% versus 28%, P less than 0.01 and 8% versus 3%, not significant, respectively). These changes reflected decrements in very low density lipoproteins alone. Despite similar increments in free fatty acid levels, (350% versus 270%, not significant) serum ketone body (beta-hydroxybutyrate and acetoacetate) concentrations increased 7-fold on the high fat diet compared to the high carbohydrate diet, P less than 0.001. The hyperketonemia of these men in response to the high fat, low calorie diet suggested the occurrence of a shift in hepatic free fatty acid metabolism toward ketogenesis rather than triglyceride synthesis. The associated decrease in the insulin: glucagon molar ratio raised the question of a possible role for these hormones in the adaptation.
PMID: 835502 [PubMed - indexed for MEDLINE]</div>

[Benson]

Thanks Dash. I was just getting ready to shoot you a PM and ask you what the longest metabolic ward study you knew of was...looks like a few weeks is the limit (no surprise).

Did they stop doing these after the 80s for some reason?

[rpen22]

<div class='quotetop'>QUOTE (dashforce)</div><div class='quotemain'>I'll have to see if I can't get the FT on this one to see if weight loss was measured:
<div class='quotetop'>QUOTE </div><div class='quotemain'>
Metabolism. 1992 Apr;41(4):406-14. Links
Protein sparing during treatment of obesity: ketogenic versus nonketogenic very low calorie diet.

Vazquez JA, Adibi SA.
Department of Medicine, Montefiore University Hospital, Pittsburgh, PA 15213.
Although it is generally agreed that both ketogenic and nonketogenic very low calorie diets promote weight reduction, there is no consensus on a preference of one diet over the other in regard to protein sparing. In the present study, we compared the effects of isocaloric (600 kcal/d) and isonitrogenous (8 g nitrogen/d) ketogenic (low carbohydrate) and nonketogenic diets on parameters of protein and amino acid metabolism, in 16 morbidly obese women maintained on these diets for 4 weeks while confined to a metabolic ward. Cumulative urinary nitrogen excretion (g/4 wk) was significantly (P less than .01) greater (248 +/- 6 v 207 +/- 12, mean +/- SEM, n = 8), and cumulative nitrogen balance significantly (P less than .02) more negative (-50.4 +/- 4.4 v -18.8 +/- 5.7), during treatment with the ketogenic than with the nonketogenic diet. Plasma leucine concentration (mumol/L) was significantly higher (P less than .05) during treatment with the ketogenic than with the nonketogenic diet at day 14 (210 +/- 17 v 150 +/- 8), but not at day 28 (174 +/- 9 v 148 +/- 8). Whole-body rates of leucine oxidation (mmol/h) were significantly higher (P less than .05) during treatment with the ketogenic than with the nonketogenic diet at day 14 (1.29 +/- 0.20 v 0.92 +/- 0.10) and at day 28 (1.00 +/- 0.16 v 0.75 +/- 0.10). Conversely, proteolysis, as measured by leucine turnover rate and urinary excretion of 3-methylhistidine, was not significantly different between the diets.(ABSTRACT TRUNCATED AT 250 WORDS)
PMID: 1556948 [PubMed - indexed for MEDLINE]</div></div>

"The weight loss during treatment with each diet was not significantly different. Total weight loss averaged 8.5 +/- 0.3 kg after 4 weeks of treatment with the ketogenic diet, and 8.3 +/- 0.5 kg after 4 weeks of treatment with the nonketogenic diet."

For some reason I can't attach files in this thread, but let me know if you'd like the rest of the FT.

[dashforce]

FT studies can be attached in my log here. I appreciate it.

[dashforce]

B - these are just the studies I pulled up on my 1st pubmed search. I'll continue looking for longer term stuff.

[Benson]

<div class='quotetop'>QUOTE (dashforce @ Mar 6 2009, 10:12 PM) <{POST_SNAPBACK}></div><div class='quotemain'>B - these are just the studies I pulled up on my 1st pubmed search. I'll continue looking for longer term stuff.</div>

And newer stuff...as we know from the corn-oil study, some of the diet stuff coming out in the 1970s is a little odd.

I'd be surprised if there is a metabolic ward study that is longer than four weeks...my guess is it would be hard to get someone to agree to stay in for longer. Which will mean that longer term weight loss will have to be extrapolated...

[dashforce]

<div class='quotetop'>QUOTE (Benson @ Mar 6 2009, 08:34 PM) <{POST_SNAPBACK}></div><div class='quotemain'>And newer stuff...as we know from the corn-oil study, some of the diet stuff coming out in the 1970s is a little odd.</div>

This doesn't specifically use the term "metabolic ward," but it seems like the same deal...

FFT

<div class='quotetop'>QUOTE </div><div class='quotemain'>Am J Clin Nutr. 1996 Feb;63(2):174-8.Click here to read Links

Similar weight loss with low- or high-carbohydrate diets.
Golay A, Allaz AF, Morel Y, de Tonnac N, Tankova S, Reaven G.

Department of Medicine, Geneva University Hospital, Switzerland.

The goal of this study was to evaluate the effect of diets that were equally low in energy but widely different in relative amounts of fat and carbohydrate on body weight during a 6-wk period of hospitalization. Consequently, 43 adult, obese persons were randomly assigned to receive diets containing 4.2 MJ/d (1000 kcal/d) composed of either 32% protein, 15% carbohydrate, and 53% fat, or 29% protein, 45% carbohydrate, and 26% fat. There was no significant difference in the amount of weight loss in response to diets containing either 15% (8.9 +/- 0.6 kg) or 45% (7.5 +/- 0.5 kg) carbohydrate. Furthermore, significant decreases in total body fat and waist-to-hip circumference were seen in both groups, and the magnitude of the changes did not vary as a function of diet composition. Fasting plasma glucose, insulin, cholesterol, and triacylglycerol concentrations decreased significantly in patients eating low-energy diets that contained 15% carbohydrate, but neither plasma insulin nor triacylglycerol concentrations fell significantly in response to the higher-carbohydrate diet. The results of this study showed that it was energy intake, not nutrient composition, that determined weight loss in response to low-energy diets over a short time period.

PMID: 8561057 [PubMed - indexed for MEDLINE]</div>

[dashforce]

Finally got around to reviewing these.

This one deserves special mention:

<div class='quotetop'>QUOTE </div><div class='quotemain'>This one (FFT) might be interesting discussion -- less than half the carbs, but an appropriate weight loss: deficit ratio (whereas a low CHO enthusiast might expect a significant weight loss: deficit ratio for the lower CHO diet).
QUOTE
Am J Clin Nutr. 1992 Oct;56(4):636-40. Links
Body composition, nitrogen metabolism, and energy utilization with feeding of mildly restricted (4.2 MJ/d) and severely restricted (2.1 MJ/d) isonitrogenous diets.

PMID: 1414962 [PubMed - indexed for MEDLINE]</div>

Among the findings were that weight and fat loss was directly proportional to expected weight loss per calorie deficit.

Further, if one does the math based on the calorie deficit per unit weight loss, then factors in the percent fat loss per unit weight loss, you find a value for calorie / unit fat quite similar to the oft-quoted 3600 kcal / lb.

Strong support for calorie balance "hypothesis," IMO.

[dashforce]

In response a recent Pro-LC, small sample size, 1970s study... [img]style_emoticons/<#EMO_DIR#>/wink.gif[/img]

Now this is well controlled. Only major disadvantage (thoough a big one) is that the crossover design prevents long-term analysis, giving each individual only a 10-day sample of each diet, although the sample as a whole sees 30 days of exposure and thereby eliminates artifacts produced by diet order (see Table 2). However, it allows the 6 different subjects to act as a much larger sample and obliterates sample error, since each gets his/her chance at each dietary intervention.

<div class='quotetop'>QUOTE </div><div class='quotemain'>J Clin Invest. 1976 Sep;58(3):722-30. Links
Composition of weight lost during short-term weight reduction. Metabolic responses of obese subjects to starvation and low-calorie ketogenic and nonketogenic diets.

Yang MU, Van Itallie TB.
The effects of starvation, an 800-kcal mixed diet and an 800-kcal ketogenic (low carbohydrate-high fat) diet on the composition of weight lost were determined in each of six obese subjects during three 10-day periods.The energy-nitrogen balance method was used to quantify the three measurable components of weight loss; protein, fat, and water. On the 800-kcal ketogenic diet, subjects lost (mean +/- SE) 466.6 +/-51.3 g/day; on the isocaloric mixed diet, which provided carbohydrate and fat in conventional proportions, they lost 277.9+/- 32.1 g/day. Composition of weight lost (percentage) during the ketogenic diet was water 61.2, fat 35.0, protein 3.8. During the mixed diet, composition of loss was water 37.1, fat 59.5, protein 3.4...
PMID: 956398 [PubMed - indexed for MEDLINE]</div>

See Figure 4 in the FFT, showing fat loss to be exactly equivalent across isocaloric, isonitrogenous dietary treatments.

[dashforce]

Here's another:

FFT
<div class='quotetop'>QUOTE </div><div class='quotemain'>Am J Clin Nutr. 1967 Oct;20(10):1104-12. Links
Fat, carbohydrate, salt, and weight loss.

Bortz WM, Wroldson A, Morris P, Issekutz B Jr.
PMID: 6069652 [PubMed - indexed for MEDLINE]</div>

<div class='quotetop'>QUOTE </div><div class='quotemain'>Following the early control periods, the
subjects were pl:tce(l on diets in which 80% of
the total calories were comsiprised of carboliydrate
or fat to the complete exclusion of the
other. These dietary periods were 24 days.</div>

<div class='quotetop'>QUOTE </div><div class='quotemain'>It is seen that aside
from random variation, weight loss was
linear with time with respect to isocaloric
sitbstitution of fat for carbohydrate
and vice versa. Excluding the early rapid
weight loss of the first hypocalonic period,
the mean daily weight loss for all fat diet
periods was 0.59 lb., while that for the
carbohyc!rate period was 0.55 lb.</div>
<div class='quotetop'>QUOTE </div><div class='quotemain'>These studies support the fundamentalist
concept of the equivalency of foodstuffs
as sources of energy. More specifically,
they deny the metabolic superiority
of a low-carbohydrate diet in the promotion
of weight loss.</div>

[Benson]

If we are putting up old studies from the 1970s, we need to include the one where they fed the participants straight corn oil at a rate of like 5,000kcal/day and they didn't gain weight but when they traded fat calories for carbs, their weight shot up.

[dashforce]

<div class='quotetop'>QUOTE (Benson @ May 21 2009, 08:33 PM) <{POST_SNAPBACK}></div><div class='quotemain'>If we are putting up old studies from the 1970s, we need to include the one where they fed the participants straight corn oil at a rate of like 5,000kcal/day and they didn't gain weight but when they traded fat calories for carbs, their weight shot up.</div>

Link to study in question.

Note that this was not true of olive oil, but exclusive to corn oil (see Figure 2), and that the subjects' sodium intake was likely very low and may have resulted in significant diuresis.

It looks like any of the subjects that lasted more than ~10 days actually did gain weight. Not as much as expected, but there was no body comp analysis to determine whether there was redistribution of water -> fat weight (which I expect).

Further, nowhere in the study do I see where carbs caused the weight to "shoot up." AAMOF, on diet 4 (the one with the highest carb content, 156g), 3 out of 4 of the subjects continued to lose weight, and the average for the 4 was still weight loss. On this count, I think your quoted statement (the part in bold) is a bit of an exaggeration [img]style_emoticons/<#EMO_DIR#>/wink.gif[/img].

[painija]

Just bumping this up... To see if Dashforce (or anyone else) has found some new studies to support the calorie theory.

[sillewater]

Eades has written some pretty good critisisms about these metabolic ward studies that I think should be considered:
http://www.proteinpower.com/drmike/weight-...-dismemberment/

[dashforce]

<div class='quotetop'>QUOTE (sillewater @ Feb 22 2010, 01:59 PM) <{POST_SNAPBACK}></div><div class='quotemain'>Eades has written some pretty good critisisms about these metabolic ward studies that I think should be considered:
http://www.proteinpower.com/drmike/weight-...-dismemberment/</div>

I don't see anything particularly novel about his criticisms, certainly nothing substantial that hasn't been discussed ad nauseum in the "superiority" thread. I don't see adequate attention given to isonitrogenicity, nor to the fact that indirect calorimetry suggests that any "metabolic advantage" of isonitrogenous LC diets must be so undetectably small that it couldn't possibly approach anything with practical significance. Advancements in technology will continue to flesh out the limits of how large this could possibly be... but as we well know, you can't prove a negative.

<div class='quotetop'>QUOTE </div><div class='quotemain'>This post has gone on way, way too long, but I think it’s pretty obvious that these studies fail to ‘prove’ that a metabolic advantage does not exist. I would say, if anything, that they ‘prove’ just the opposite.</div>
What?? I'd say the author of this piece seems to suffer from confirmation bias every bit as badly as the researchers he attempts to criticize.

[dashforce]

Meta-analysis of accuracy of self-reported diet methods vs doubly labeled water:

Trabulsi and Schoeller. Evaluation of dietary assessment instruments against doubly labeled water, a biomarker of habitual energy intake. Am J Physiol Endocrinol Metab (2001) vol. 281 (5) pp. E891-9

EDIT:
Parts of the conclusion are relevant to several discussions involved the feasibility of selective misreporting of food types. Selective underreporting of "fats and sugars" may help explain the consistent difference between LCD and HCD in self-reported diet studies. However, the underreporting of fats exclusively would seem to support the "metabolic advantage" idea, although I'm not convinced that these conclusions (likely generated from mixed diet data) can be generalized to what happens in a LCD / keto diet. Taken by itself this doesn't really say much regarding the LCD superiority idea, but I simply wanted to point out that selective misreporting of certain macros is feasible.

<div class='quotetop'>QUOTE </div><div class='quotemain'>This review has demonstrated that, regardless of the dietary methodology employed to assess habitual diet, true energy intake is consistently underreported by certain groups within the population. As the ability to identify underreporters of dietary energy intake im- proves, it may seem that the next logical step would be to address what to do about underreporters of true intake. Proposed ideas to account for the reporting error have focused around two methods: 1) removing the underreporters from the data set, or 2) statistically correcting “reported” intake to represent true intake. Although the merits of these approaches are being investigated, it is our opinion that which foods are being underreported is of even greater importance than the magnitude of underreporting. For example, if the observed underreporting of energy intake on di- etary surveys is due to a random omission of foods or an underestimation of portion size, techniques to ac- count for this error, such as energy adjustment, should improve nutrient intake estimates. If, however, only certain types of foods are consistently underreported by some population groups, suggestive of a systematic bias, misleading conclusions will be drawn with regard to diet and disease relationships. Indeed, a recent study found that underreporters of energy intake re- ported consuming fewer foods rich in fat and sugar and reported higher vitamin C and fiber intakes than par- ticipants with a reported energy intake in the normal range (13). Goris et al. (12) found similar results with respect to fat intake.</div>

[dashforce]

Not quite a met ward, but quite good. DEXA for body comp. No SS differences in ∆BW, ∆BF, ∆BF%, ∆WC...

FFT

Diabetes. 2009 Dec;58(12):2741-8. Epub 2009 Aug 31.
Low-fat versus low-carbohydrate weight reduction diets: effects on weight loss, insulin resistance, and cardiovascular risk: a randomized control trial.
Bradley U, Spence M, Courtney CH, McKinley MC, Ennis CN, McCance DR, McEneny J, Bell PM, Young IS, Hunter SJ.
Source
Regional Centre for Endocrinology and Diabetes, Royal Victoria Hospital, Belfast, U.K.
Abstract
OBJECTIVE:
Low-fat hypocaloric diets reduce insulin resistance and prevent type 2 diabetes in those at risk. Low-carbohydrate, high-fat diets are advocated as an alternative, but reciprocal increases in dietary fat may have detrimental effects on insulin resistance and offset the benefits of weight reduction.

RESEARCH DESIGN AND METHODS:
We investigated a low-fat (20% fat, 60% carbohydrate) versus a low-carbohydrate (60% fat, 20% carbohydrate) weight reduction diet in 24 overweight/obese subjects ([mean +/- SD] BMI 33.6 +/- 3.7 kg/m(2), aged 39 +/- 10 years) in an 8-week randomized controlled trial. All food was weighed and distributed, and intake was calculated to produce a 500 kcal/day energy deficit. Insulin action was assessed by the euglycemic clamp and insulin secretion by meal tolerance test. Body composition, adipokine levels, and vascular compliance by pulse-wave analysis were also measured.

RESULTS:
Significant weight loss occurred in both groups (P < 0.01), with no difference between groups (P = 0.40). Peripheral glucose uptake increased, but there was no difference between groups (P = 0.28), and suppression of endogenous glucose production was also similar between groups. Meal tolerance-related insulin secretion decreased with weight loss with no difference between groups (P = 0.71). The change in overall systemic arterial stiffness was, however, significantly different between diets (P = 0.04); this reflected a significant decrease in augmentation index following the low-fat diet, compared with a nonsignificant increase within the low-carbohydrate group.

CONCLUSIONS:
This study demonstrates comparable effects on insulin resistance of low-fat and low-carbohydrate diets independent of macronutrient content. The difference in augmentation index may imply a negative effect of low-carbohydrate diets on vascular risk.

PMID: 19720791 [PubMed - indexed for MEDLINE] PMCID: PMC2780863

[michael2828]

big wall of text scary scary stuff

[Benson]

big wall of text scary scary stuff

If you think that's scary, you should look up one of ATB's threads...seriously though, there is a lot of knowledge on this site contained in some pretty dense threads but I'd encourage anyone who wants to really learn about some of these subjects to put in the effort and read them.