- Liittynyt
- 7.10.2002
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Täällä oli vastikään pitkä ketju kaloreista ja kehonpainosta yms. Laitetaan lisää löylyä debaattiin... 
(Nutrition & Metabolism Society poster presentation 2006)
A meta-analysis of low vs high carbohydrate diets
Fine EJ 1,2, Feinman RD2, Isasi C3, Wylie-Rosett J3
1Department of Nuclear Medicine, Jacobi Medical Center, Albert Einstein College of Medicine, Bronx, NY2Department of Biochemistry, Downstate Medical Center, Brooklyn , NY3Department of Epidemiology and Population Health, Albert Einstein College of Medicine, Bronx, NY
Background: Carbohydrate (CHO) restricted diets have been reported to be more effective, calorie-for-calorie, than other weight loss approaches. Theoretical objections that increased efficacy violates thermodynamic laws have been shown to be based on misunderstanding the underlying physical principles. Variable efficiency in conversion of macronutrients to useable ATP is biologically expected in a variety of circumstances. Further, plausible mechanisms may be proposed for this effect to be seen specifically in CHO restriction. The presence or absence of metabolic inefficiency due to CHO restriction must be determined empirically. In 2003, Bravata et al’s1 systematic review of low CHO (LC) diets concluded that information was insufficient to decide if LC vs high CHO (HC) produced weight loss in excess of expectations based on caloric reduction. This was misinterpreted to mean that there was sufficient information to exclude a specific effect of CHO reduction. Further, methodologically, the study pooled low CHO data across experiments instead of evaluating energy matched trials, statistically diluting the physiologic value of energy matched studies with LC and HC arms.
Methods: Meta-analysis of randomized controlled (RC) or randomized crossover (RX) studies with LC (<130 g/day) vs higher CHO arms; > 21 days, > 800kCal. Binomial statistical analysis of excess weight loss, rank correlations of excess weight loss with CHO and diet duration.
Results: 9 of 10 RC/RX studies showed excess weight loss on the LC arm (p<0.01). Mean weight loss LC = 7.2 ± 0.4 kg, HC = 5.6 ± 0.3 kg (Mean difference: LC-HC = 1.6 kg; p<0.01); 4 of 10 were inpatient studies with prepared diets. Excess weight loss correlated best with CHO (HC-LC) x duration (r=0.85, by rank, r=0.94 by log regression): wt loss = -16.9 kg + 5.1 (log CHO x days)
Results cannot be explained by an early diuresis effect, by lower compliance on HC dietary arm, or by dietary protein content.
Conclusion: In contrast to previous modes of analysis, this study shows that metabolic inefficiency of LC diets must be given serious consideration to account for the excess weight loss seen.
1. Bravata DM, Sanders L, Huang J, Krumholz HM, Olkin I, Gardner CD: Efficacy and safety of low-carbohydrate diets: a systematic review. JAMA 2003, 289(14):1837-1850.
(Nutrition & Metabolism Society poster presentation 2006)A meta-analysis of low vs high carbohydrate diets
Fine EJ 1,2, Feinman RD2, Isasi C3, Wylie-Rosett J3
1Department of Nuclear Medicine, Jacobi Medical Center, Albert Einstein College of Medicine, Bronx, NY2Department of Biochemistry, Downstate Medical Center, Brooklyn , NY3Department of Epidemiology and Population Health, Albert Einstein College of Medicine, Bronx, NY
Background: Carbohydrate (CHO) restricted diets have been reported to be more effective, calorie-for-calorie, than other weight loss approaches. Theoretical objections that increased efficacy violates thermodynamic laws have been shown to be based on misunderstanding the underlying physical principles. Variable efficiency in conversion of macronutrients to useable ATP is biologically expected in a variety of circumstances. Further, plausible mechanisms may be proposed for this effect to be seen specifically in CHO restriction. The presence or absence of metabolic inefficiency due to CHO restriction must be determined empirically. In 2003, Bravata et al’s1 systematic review of low CHO (LC) diets concluded that information was insufficient to decide if LC vs high CHO (HC) produced weight loss in excess of expectations based on caloric reduction. This was misinterpreted to mean that there was sufficient information to exclude a specific effect of CHO reduction. Further, methodologically, the study pooled low CHO data across experiments instead of evaluating energy matched trials, statistically diluting the physiologic value of energy matched studies with LC and HC arms.
Methods: Meta-analysis of randomized controlled (RC) or randomized crossover (RX) studies with LC (<130 g/day) vs higher CHO arms; > 21 days, > 800kCal. Binomial statistical analysis of excess weight loss, rank correlations of excess weight loss with CHO and diet duration.
Results: 9 of 10 RC/RX studies showed excess weight loss on the LC arm (p<0.01). Mean weight loss LC = 7.2 ± 0.4 kg, HC = 5.6 ± 0.3 kg (Mean difference: LC-HC = 1.6 kg; p<0.01); 4 of 10 were inpatient studies with prepared diets. Excess weight loss correlated best with CHO (HC-LC) x duration (r=0.85, by rank, r=0.94 by log regression): wt loss = -16.9 kg + 5.1 (log CHO x days)
Results cannot be explained by an early diuresis effect, by lower compliance on HC dietary arm, or by dietary protein content.
Conclusion: In contrast to previous modes of analysis, this study shows that metabolic inefficiency of LC diets must be given serious consideration to account for the excess weight loss seen.
1. Bravata DM, Sanders L, Huang J, Krumholz HM, Olkin I, Gardner CD: Efficacy and safety of low-carbohydrate diets: a systematic review. JAMA 2003, 289(14):1837-1850.
Itelläkin alkaa "kylkkärit" kasvamaan heti kun mässää paljon hiilareita (esim. Jouluna jne.). Ja niihin hiilareihin tulee sellainen kumma kierre, että kun niitä syö paljon niin niitä pitää vetää jatkuvasti napaan... 
