Long-term weight maintenance and cardiovascular risk factors are not different following weight loss on carbohydrate-restricted diets high in either monounsaturated fat or protein in obese hyperinsulinaemic men and women.
The aim of this study was to determine after 52 weeks whether advice to follow a lower carbohydrate diet, either high in monounsaturated fat or low fat, high in protein had differential effects in a free-living community setting. Following weight loss on either a high monounsaturated fat, standard protein (HMF; 50 % fat, 20 % protein (67 g/d), 30 % carbohydrate) or a high protein, moderate fat (HP) (40 % protein (136 g/d), 30 % fat, 30 % carbohydrate) energy-restricted diet (6000 kJ/d) subjects were asked to maintain the same dietary pattern without intensive dietary counselling for the following 36 weeks. Overall weight loss was 6.2 (SD 7.3) kg (P < 0.01 for time with no diet effect, 7.6 (SD 8.1) kg, HMF v. 4.8 (SD 6.6) kg, HP). In a multivariate regression model predictors of weight loss at the end of the study were sex, age and reported percentage energy from protein (R2 0.22, P < 0.05 for the whole model). Fasting plasma insulin decreased (P < 0.01, with no difference between diets), 13.9 (SD 4.6) to 10.2 (SD 5.2) mIU/l, but fasting plasma glucose was not reduced. Neither total cholesterol nor LDL-cholesterol were different but HDL was higher, 1.19 (SD 0.26) v. 1.04 (SD 0.29) (P < 0.001 for time, no diet effect), while TAG was lower, 1.87 (SD 1.23) v. 2.22 (SD 1.15) mmol/l (P < 0.05 for time, no diet effect). C-reactive protein decreased (3.97 (SD 2.84) to 2.43 (SD 2.29) mg/l, P < 0.01). Food records showed that compliance to the prescribed dietary patterns was poor. After 1 year there remained a clinically significant weight loss and improvement in cardiovascular risk factors with no adverse effects of a high monounsaturated fat diet.
Keogh
Jennifer B
JB
CSIRO Human Nutrition, Adelaide, South Australia, 5000, Australia. jennifer.keogh@csiro.au
Luscombe-Marsh
Natalie D
ND
Noakes
Manny
M
Wittert
Gary A
GA
Clifton
Peter M
PM
D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000032:analysis; D001823:Body Composition / Q000502:physiology; D001842:Bone and Bones / Q000378:metabolism; D002318:Cardiovascular Diseases / Q000209:etiology*; D004040:Dietary Carbohydrates / Q000008:administration & dosage*; D004044:Dietary Proteins / Q000008:administration & dosage*; D005229:Fatty Acids, Monounsaturated / Q000008:administration & dosage; D005230:Fatty Acids, Nonesterified / Q000097:blood; D005260:Female; D006801:Humans; D006946:Hyperinsulinism / Q000150:complications / Q000178:diet therapy* / Q000378:metabolism; D007328:Insulin / Q000097:blood; D008055:Lipids / Q000097:blood; D008134:Long-Term Care; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000150:complications / Q000178:diet therapy* / Q000378:metabolism; D010349:Patient Compliance / Q000523:psychology; D012307:Risk Factors; D015431:Weight Loss / Q000502:physiology
D015415:Biomarkers; D004040:Dietary Carbohydrates; D004044:Dietary Proteins; D005229:Fatty Acids, Monounsaturated; D005230:Fatty Acids, Nonesterified; D007328:Insulin; D008055:Lipids