Relatively high-protein or 'low-carb' energy-restricted diets for body weight loss and body weight maintenance?
Soenen S, Bonomi AG, Lemmens SG, Scholte J, Thijssen MA, van Berkum F, Westerterp-Plantenga MS.
Source
Department of Human Biology, Nutrition and Toxicology Research Institute Maastricht (NUTRIM), Maastricht University, P.O. Box 616, 6200 MD Maastricht, The Netherlands; Top Institute Food and Nutrition (TIFN), Wageningen, The Netherlands.
Abstract
BACKGROUND:
'Low-carb' diets have been suggested to be effective in body weight (BW) management. However, these diets are relatively high in protein as well.
OBJECTIVE:
To unravel whether body-weight loss and weight-maintenance depends on the high-protein or the 'low-carb' component of the diet.
DESIGN:
Body-weight (BW), fat mass (FM), blood- and urine-parameters of 132 participants (age=50 ± 12 yr; BW=107 ± 20 kg; BMI=37 ± 6 kg/m(2); FM=47.5 ± 11.9 kg) were compared after 3 and 12 months between four energy-restricted diets with 33% of energy requirement for the first 3 months, and 67% for the last 9 months: normal-protein normal-carbohydrate (NPNC), normal-protein low-carbohydrate (NPLC); high-protein normal-carbohydrate (HPNC), high-protein low-carbohydrate (HPLC); 24h N-analyses confirmed daily protein intakes for the normal-protein diets of 0.7 ± 0.1 and for the high-protein diets of 1.1 ± 0.2g/kg BW (p<0.01).
RESULTS:
BW and FM decreased over 3 months (p<0.001): HP (-14.1 ± 4 kg; -11.9 ± 1.7 kg) vs. NP (-11.5 ± 4 kg; -9.3 ± 0.7 kg) (p<0.001); LC (-13.5 ± 4 kg; -11.0 ± 1.2 kg) vs. NC (-12.3 ± 3 kg; -10.3 ± 1.1 kg) (ns). Diet × time interaction showed HPLC (-14.7 ± 5 kg; -11.9 ± 1.6 kg) vs. HPNC (-13.8 ± 3 kg; -11.9 ± 1.8 kg) (ns); NPLC (-12.2 ± 4 kg; -10.0 ± 0.8 kg) vs. NPNC (-10.7 ± 4 kg; -8.6 ± 0.7 kg) (ns); HPLC vs. NPLC (p<0.001); HPNC vs. NPNC (p<0.001). Decreases over 12 months (p<0.001) showed HP (-12.8 ± 4 kg; -9.1 ± 0.8 kg) vs. NP (-8.9 ± 3 kg; -7.7 ± 0.6 kg) (p<0.001); LC (-10.6 ± 4 kg; -8.3 ± 0.7 kg) vs. NC (11.1 ± 3 kg; 9.3 ± 0.7 kg) (ns). Diet × time interaction showed HPLC (-11.6 ± 5 kg ; -8.2 ± 0.7 kg) vs. HPNC (-14.1 ± 4 kg; -10.0 ± 0.9 kg) (ns); NPNC (-8.2 ± 3 kg; -6.7 ± 0.6 kg) vs. NPLC (-9.7 ± 3 kg; -8.5 ± 0.7 kg) (ns); HPLC vs. NPLC (p<0.01); HPNC vs. NPNC (p<0.01). HPNC vs. all other diets reduced diastolic blood pressure more. Relationships between changes in BW, FM, FFM or metabolic parameters and energy percentage of fat in the diet were not statistically significant. Metabolic profile and fat-free-mass were improved following weight-loss.
CONCLUSION:
Body-weight loss and weight-maintenance depends on the high-protein, but not on the 'low-carb' component of the diet, while it is unrelated to the concomitant fat-content of the diet.
[The effects of a low-fat versus a low carbohydrate diet in obese adults].
[Article in Spanish]
De Luis DA, Aller R, Izaola O, González Sagrado M, Conde R.
Source
Red temática de Investigación Corporativa en Envejecimiento RD056/0013, Instituto de Endocrinología y Nutrición, Facultad de Medicina, Universidad de Valladolid, Unidad de Investigación, Hospital Río Hortera, Valladolid, España.
[email protected]
Abstract
BACKGROUND AND OBJECTIVE:
The aim of our study was to compare the effect of a high fat and a high protein diet vs a fat restricted diet on weight loss in obese patients.
SUBJECTS AND METHODS:
A population of 74 obesity non diabetic outpatients was analyzed in a prospective way. Patients were randomly allocated to two groups: a) diet I (low fat diet: 1500kcal/day, 52% carbohydrates, 20% proteins, 27% fats) with a distribution of fats and b) diet II (high fat and high protein diet: 1507kcal/day, 38% carbohydrates, 26% proteins, 36% fats). After three months with diet, weight, blood pressure, glucose, C reactive protein, insulin, insulin resistance, total cholesterol, LDL-cholesterol, HDL-cholesterol and triglycerides were evaluated.
RESULTS:
There were randomized 35 patients (4 males and 31 females) in the group I and 39 patients (6 males and 33 females) in diet group II. In group I, systolic pressure, BMI, weight, fat free mass, fat mass total body water, intracellular body water and waist circumference decreased significantly. In group II, glucose, total cholesterol, LDL cholesterol, systolic blood, BMI, weight, fat mass, total body water and waist circumference decreased significantly. Differences among averages of parameters before treatment with both diets were not detected.
CONCLUSIONS:
No differences were detected on weight loss between a fat-restricted diet and a high fat and high protein enhanced diet.