[oldaccount]

Originally Posted by Bobby_Light

Please refute my statement if you feel it is invalid.

ok.

***

http://www.ajcn.org/cgi/content/full...8deeb08a678686

We conclude that a calorie is a calorie. From a purely thermodynamic point of view, this is clear because the human body or, indeed, any living organism cannot create or destroy energy but can only convert energy from one form to another. In comparing energy balance between dietary treatments, however, it must be remembered that the units of dietary energy are metabolizable energy and not gross energy. This is perhaps unfortunate because metabolizable energy is much more difficult to determine than is gross energy, because the Atwater factors used in calculating metabolizable energy are not exact. As such, our food tables are not perfect, and small errors are associated with their use.

In addition, we concede that the substitution of one macronutrient for another has been shown in some studies to have a statistically significant effect on the expenditure half of the energy balance equation. This has been observed most often for high-protein diets. Evidence indicates, however, that the difference in energy expenditure is small and can potentially account for less than one-third of the differences in weight loss that have been reported between high-protein or low-carbohydrate diets and high-carbohydrate or low-fat diets. As such, a calorie is a calorie. Further research is needed to identify the mechanisms that result in greater weight loss with one diet than with another.

Johnston CS et. al. Ketogenic low-carbohydrate diets have no metabolic advantage over nonketogenic low-carbohydrate diets. American Journal of Clinical Nutrition. (2006) 83: 1055-1061

Background:Low-carbohydrate diets may promote greater weight loss than does the conventional low-fat, high-carbohydrate diet. Objective:We compared weight loss and biomarker change in adults adhering to a ketogenic low-carbohydrate (KLC) diet or a nonketogenic low-carbohydrate (NLC) diet. Design:Twenty adults [body mass index (in kg/m2): 34.4 ± 1.0] were randomly assigned to the KLC (60% of energy as fat, beginning with 5% of energy as carbohydrate) or NLC (30% of energy as fat; 40% of energy as carbohydrate) diet. During the 6-wk trial, participants were sedentary, and 24-h intakes were strictly controlled. Results:Mean (±SE) weight losses (6.3 ± 0.6 and 7.2 ± 0.8 kg in KLC and NLC dieters, respectively; P = 0.324) and fat losses (3.4 and 5.5 kg in KLC and NLC dieters, respectively; P = 0.111) did not differ significantly by group after 6 wk. Blood ß-hydroxybutyrate in the KLC dieters was 3.6 times that in the NLC dieters at week 2 (P = 0.018), and LDL cholesterol was directly correlated with blood ß-hydroxybutyrate (r = 0.297, P = 0.025). Overall, insulin sensitivity and resting energy expenditure increased and serum -glutamyltransferase concentrations

decreased in both diet groups during the 6-wk trial (P < 0.05). However, inflammatory risk (arachidonic acid:eicosapentaenoic acid ratios in plasma phospholipids) and perceptions of vigor were more adversely affected by the KLC than by the NLC diet. Conclusions:KLC and NLC diets were equally effective in reducing body weight and insulin resistance, but the KLC diet was associated with several adverse metabolic and emotional effects. The use of ketogenic diets for weight loss is not warranted.

http://www.ncbi.nlm.nih.gov/pubmed/15867892

Energetics of obesity and weight control: does diet composition matter?
Schoeller DA, Buchholz AC.

Department of Nutritional Sciences, University of Wisconsin-Madison, 53706, USA. dschoell@nutrisci.wisc.edu

Greater average weight losses (2.5 kg over 12 weeks) have been reported for low-carbohydrate diets (<90 g/day) compared with traditional low-fat (<25% of energy), hypocaloric diets, implying a 233 kcal/day greater energy deficit. It has therefore been suggested that a low-carbohydrate diet may provide a metabolic advantage (an increase in energy expenditure), resulting in a positive effect on weight loss and maintenance. However, a review of studies in which 24-hour energy expenditure was measured did not provide evidence to support a metabolic advantage of low-carbohydrate diets and showed little evidence of a metabolic advantage of high-protein (>25% of energy) diets. Nonetheless, diets high in protein, but either low or modest in carbohydrate, have resulted in greater weight losses than traditional low-fat diets. We speculate that it is the protein, and not carbohydrate, content that is important in promoting short-term weight loss and that this effect is likely due to increased satiety caused by increased dietary protein. It has been suggested that the increased satiety might help persons to be more compliant with a hypocaloric diet and achieve greater weight loss. The current evidence, combined with the need to meet all nutrient requirements, suggests that hypocaloric weight-loss diets should be moderate in carbohydrate (35% to 50% of energy), moderate in fat (25% to 35% of energy), and protein should contribute 25% to 30% of energy intake. More studies of the efficacy of weight-loss and weight-maintenance diets that address protein content are needed. In addition, controlled studies of total energy expenditure or physical activity measured under free-living conditions that directly compare high-protein diets with those containing low and moderate carbohydrate content should also be performed.

http://www.ncbi.nlm.nih.gov/pubmed/17413100

Effect on 24-h energy expenditure of a moderate-fat diet high in monounsaturated fatty acids compared with that of a low-fat, carbohydrate-rich diet: a 6-mo controlled dietary intervention trial.
Rasmussen LG, Larsen TM, Mortensen PK, Due A, Astrup A.

Department of Human Nutrition, Faculty of Life Sciences, University of Copenhagen, Frederiksberg, Denmark. logr@life.ku.dk

BACKGROUND: Dietary fat has a lower thermogenic effect than does carbohydrate. A moderate-fat diet, high in monounsaturated fatty acids (MUFA diet), may decrease energy expenditure (EE) and thereby induce weight gain. OBJECTIVE: We aimed to compare changes in 24-h EE and substrate oxidation after a 6-mo controlled dietary intervention with either a MUFA or a low-fat (LF) diet. DESIGN: Twenty-seven overweight [body mass index (in kg/m(2)): 28.1 +/- 0.4] nondiabetic subjects aged 18-36 y followed an 8-wk low-calorie diet and a 2-wk weight-stabilizing diet and then were randomly assigned to a MUFA (n = 12) or LF (n = 15) diet for 6 mo. Substrate oxidation and 24-h EE were measured by whole-body indirect calorimetry. The first measurement (0 mo) was taken during the weight-stabilizing diet, and the second measurement was taken after the 6-mo intervention. RESULTS: A tendency was seen toward a lower 24-h EE with the MUFA than with the LF diet (P = 0.0675), but this trend did not remain after adjustment for the initial loses of fat mass and fat-free mass (P = 0.2963). Meal-induced thermogenesis was significantly (P < 0.05) lower with the MUFA than with the LF diet, but no time x treatment interaction was found. A significant (P = 0.0456) treatment x time interaction was found for spontaneous physical activity. CONCLUSION: Despite a slightly lower meal-induced thermogenesis, the MUFA diet had an effect on 24-h EE that was not significantly different from that of the LF diet after a 6-mo controlled dietary intervention.

Am J Clin Nutr. 2004 May;79(5):899S-906S.Click here to read Links

Comment in:
Am J Clin Nutr. 2004 Nov;80(5):1445-6; author reply 1446.
Am J Clin Nutr. 2004 Nov;80(5):1445; author reply 1446.

Is a calorie a calorie?
Buchholz AC, Schoeller DA.

Department of Nutritional Sciences, University of Wisconsin-Madison, 1415 Linden Drive, Madison, WI 53706, USA.

The aim of this review was to evaluate data regarding potential thermodynamic mechanisms for increased rates of weight loss in subjects consuming diets high in protein and/or low in carbohydrate. Studies that compared weight loss and energy expenditure in adults consuming diets high in protein and/or low in carbohydrate with those in adults consuming diets low in fat were reviewed. In addition, studies that measured the metabolizable energy of proteins, fats, and carbohydrates were reviewed. Diets high in protein and/or low in carbohydrate produced an approximately equal to 2.5-kg greater weight loss after 12 wk of treatment. Neither macronutrient-specific differences in the availability of dietary energy nor changes in energy expenditure could explain these differences in weight loss. Thermodynamics dictate that a calorie is a calorie regardless of the macronutrient composition of the diet. Further research on differences in the composition of weight loss and on the influence of satiety on compliance with energy-restricted diets is needed to explain the observed increase in weight loss with diets high in protein and/or low in carbohydrate.

J Clin Endocrinol Metab. 2005 Mar;90(3):1475-82. Epub 2004 Dec 14. Links
The role of energy expenditure in the differential weight loss in obese women on low-fat and low-carbohydrate diets.

Brehm BJ, Spang SE, Lattin BL, Seeley RJ, Daniels SR, D'Alessio DA.
R.D., University of Cincinnati, P.O. Box 210038, Cincinnati, Ohio 45221-0038, USA. bonnie.brehm@uc.edu
We have recently reported that obese women randomized to a low-carbohydrate diet lost more than twice as much weight as those following a low-fat diet over 6 months. The difference in weight loss was not explained by differences in energy intake because women on the two diets reported similar daily energy consumption. We hypothesized that chronic ingestion of a low-carbohydrate diet increases energy expenditure relative to a low-fat diet and that this accounts for the differential weight loss. To study this question, 50 healthy, moderately obese (body mass index, 33.2 +/- 0.28 kg/m(2)) women were randomized to 4 months of an ad libitum low-carbohydrate diet or an energy-restricted, low-fat diet. Resting energy expenditure (REE) was measured by indirect calorimetry at baseline, 2 months, and 4 months. Physical activity was estimated by pedometers. The thermic effect of food (TEF) in response to low-fat and low-carbohydrate breakfasts was assessed over 5 h in a subset of subjects. Forty women completed the trial. The low-carbohydrate group lost more weight (9.79 +/- 0.71 vs. 6.14 +/- 0.91 kg; P < 0.05) and more body fat (6.20 +/- 0.67 vs. 3.23 +/- 0.67 kg; P < 0.05) than the low-fat group. There were no differences in energy intake between the diet groups as reported on 3-d food records at the conclusion of the study (1422 +/- 73 vs. 1530 +/- 102 kcal; 5954 +/- 306 vs. 6406 +/- 427 kJ). Mean REE in the two groups was comparable at baseline, decreased with weight loss, and did not differ at 2 or 4 months. The low-fat meal caused a greater 5-h increase in TEF than did the low-carbohydrate meal (53 +/- 9 vs. 31 +/- 5 kcal; 222 +/- 38 vs. 130 +/- 21 kJ; P = 0.017). Estimates of physical activity were stable in the dieters during the study and did not differ between groups. These results confirm that short-term weight loss is greater in obese women on a low-carbohydrate diet than in those on a low-fat diet even when reported food intake is similar. The differential weight loss is not explained by differences in REE, TEF, or physical activity and likely reflects underreporting of food consumption by the low-fat dieters.

1: J Nutr. 2005 Oct;135(10):2387-91. Related Articles, Links


Reduced glycemic index and glycemic load diets do not increase the effects of energy restriction on weight loss and insulin sensitivity in obese men and women.

Raatz SK, Torkelson CJ, Redmon JB, Reck KP, Kwong CA, Swanson JE, Liu C, Thomas W, Bantle JP.

General Clinical Research Center, Department of Medicine, School of Public Health, University of Minnesota, Minneapolis, MN, USA. raatz@med.umn.edu

Reducing the dietary glycemic load and the glycemic index was proposed as a novel approach to weight reduction. A parallel-design, randomized 12-wk controlled feeding trial with a 24-wk follow-up phase was conducted to test the hypothesis that a hypocaloric diet designed to reduce the glycemic load and the glycemic index would result in greater sustained weight loss than other hypocaloric diets. Obese subjects (n = 29) were randomly assigned to 1 of 3 diets providing 3138 kJ less than estimated energy needs: high glycemic index (HGI), low glycemic index (LGI), or high fat (HF). For the first 12 wk, all food was provided to subjects (feeding phase). Subjects (n = 22) were instructed to follow the assigned diet for 24 additional weeks (free-living phase). Total body weight was obtained and body composition was assessed by skinfold measurements. Insulin sensitivity was assessed by the homeostasis model (HOMA). At 12 wk, weight changes from baseline were significant in all groups but not different among groups (-9.3 +/- 1.3 kg for the HGI diet, -9.9 +/- 1.4 kg for the LGI diet, and -8.4 +/- 1.5 kg for the HF diet). All groups improved in insulin sensitivity at the end of the feeding phase of the study. During the free-living phase, all groups maintained their initial weight loss and their improved insulin sensitivity. Weight loss and improved insulin sensitivity scores were independent of diet composition. In summary, lowering the glycemic load and glycemic index of weight reduction diets does not provide any added benefit to energy restriction in promoting weight loss in obese subjects.

Comparison of 3 ad libitum diets for weight-loss maintenance, risk of cardiovascular disease, and diabetes: a 6-mo randomized, controlled trial.
Due A, Larsen TM, Mu H, Hermansen K, Stender S, Astrup A.

Department of Human Nutrition, Centre for Advanced Food Studies, Faculty of Life Sciences, University of Copenhagen, Frederiksberg C, Denmark.

BACKGROUND: The optimal dietary content and type of fat and carbohydrate for weight management has been debated for decades. OBJECTIVE: The objective was to compare the effects of 3 ad libitum diets on the maintenance of an initial weight loss of >or=8% and risk factors for CVD and diabetes during a 6-mo controlled dietary intervention. DESIGN: Nondiabetic overweight or obese [mean +/- SD body mass index (in kg/m(2)): 31.5 +/- 2.6] men (n = 55) and women (n = 76) aged 28.2 +/- 4.8 y were randomly assigned to a diet providing a moderate amount of fat (35-45% of energy) and >20% of fat as monounsaturated fatty acids (MUFA diet; n = 54), to a low-fat (20-30% of energy) diet (LF diet; n = 51), or to a control diet (35% of energy as fat; n = 26). Protein constituted 10-20% of energy in all 3 diets. All foods were provided free of charge from a purpose-built supermarket. RESULTS: More subjects dropped out of the MUFA (28%) group than out of the LF group (16%) and control group (8%) (MUFA compared with control: P < 0.05). All groups regained weight (MUFA: 2.5 +/- 0.7 kg; LF: 2.2 +/- 0.7 kg; and control: 3.8 +/- 0.8 kg; NS). Body fat regain was lower in the LF (0.6 +/- 0.6%) and MUFA (1.6 +/- 0.6%) groups than in the control group (2.6 +/- 0.5%) (P < 0.05). In the MUFA group, fasting insulin decreased by 2.6 +/- 3.5 pmol/L, the homeostasis model assessment of insulin resistance by 0.17 +/- 0.13, and the ratio of LDL to HDL by 0.33 +/- 0.13; in the LF group, these variables increased by 4.3 +/- 3.0 pmol/L (P < 0.08) and 0.17 +/- 0.10 (P < 0.05) and decreased by 0.02 +/- 0.09 (P = 0.005), respectively; and in the control group, increased by 14.0 +/- 4.3 pmol/L (P < 0.001), 0.57 +/- 0.17 (P < 0.001), and 0.05 +/- 0.14 (P = 0.036), respectively. Dietary adherence was high on the basis of fatty acid changes in adipose tissue. CONCLUSIONS: Diet composition had no major effect on preventing weight regain. However, both the LF and MUFA diets produced less body fat regain than did the control diet, and the dropout rate was lowest in the LF diet group, whereas fasting insulin decreased and the homeostasis model assessment of insulin resistance and ratio of LDL to HDL improved with the MUFA diet. This trial was registered at clinicaltrials.gov as NCT00274729.

http://www.bodyrecomposition.com/fat...a-calorie.html

for the most part, studies where protein is adequate (or at least close to it), varying carbs and fats within the context of an identical caloric intake tends to have a minimal overall effect. What effect is occasionally seen tends to be small and highly variable (some subjects do better with one diet than another but there’s no consistent advantage). With the possible exception of extreme conditions (folks looking for super-leanness or folks who are super-obese), caloric intake is the greater determinant of results than the macronutrient composition.

my point is that if calories are being strictly controlled, the source doesn’t appear to make a humongous difference in terms of body composition changes. As well, once you get protein intake to proper levels, fooling around with carbohydate and fat ratios (within the context of identical caloric intakes) don’t seem to make a huge amount of difference either. The bottom line still comes down to calories in versus calories out

I suggest reading this thread, Bobby. You might learn something: http://forums.jpfitness.com/diet-nut...tml#post748988