Comparison of the effects on insulin resistance and glucose tolerance of 6-mo high-monounsaturated-fat, low-fat, and control diets.
BACKGROUND
The effect of dietary fat and carbohydrate on glucose metabolism has been debated for decades.


OBJECTIVE
The objective was to compare the effect of 3 ad libitum diets, different in type and amount of fat and carbohydrate, on insulin resistance and glucose tolerance subsequent to weight loss.


METHODS
Forty-six nondiabetic, obese [mean (+/-SEM) body mass index (in kg/m(2)): 31.2 +/- 0.3] men (n = 20) and premenopausal women (n = 26) aged 28.0 +/- 0.7 y were randomly assigned to 1 of 3 diets after > or = 8% weight loss: 1) MUFA diet (n = 16): moderate in fat (35-45% of energy) and high in monounsaturated fatty acids ( > 20% of energy); 2) LF diet (n = 18): low-fat diet (20-30% of energy), and 3) control diet (n = 12): 35% of energy as fat ( > 15% of energy as saturated fatty acids). Protein accounted for 15% of energy in all 3 diets. A 2-h oral-glucose-tolerance test (OGTT) was performed before and after the 6-mo dietary intervention. All foods were provided by a purpose-built supermarket.


RESULTS
After 6 mo, the MUFA diet reduced fasting glucose (-3.0%), insulin (-9.4%), and the homeostasis model assessment of insulin resistance score (-12.1%). Compared with the MUFA diet, the control diet increased these variables [1.4% (P = 0.014), 21.2% (P = 0.030), and 22.8% (P = 0.015), respectively], as did the LF diet [1.4% (P = 0.090), 13.1% (P = 0.078), and 15.5% (P = 0.095), respectively]. No significant group differences were detected in glucose or insulin concentrations during the OGTT, in the Matsudas index, in body weight, or in body composition.


CONCLUSIONS
A diet high in monounsaturated fat has a more favorable effect on glucose homeostasis than does the typical Western diet in the short term and may also be more beneficial than the official recommended low-fat diet during a period of weight regain subsequent to weight loss.
Due
Anette
A
Department of Human Nutrition, Centre for Advanced Food Studies, Faculty of Life Sciences, University of Copenhagen, Frederiksberg C, Denmark.
Larsen
Thomas M
TM
Hermansen
Kjeld
K
Stender
Steen
S
Holst
Jens J
JJ
Toubro
Søren
S
Martinussen
Torben
T
Astrup
Arne
A
D000293:Adolescent; D000328:Adult; D001786:Blood Glucose / Q000378:metabolism*; D001823:Body Composition; D018752:Diet, Fat-Restricted; D004038:Diet, Reducing; D004040:Dietary Carbohydrates / Q000008:administration & dosage / Q000378:metabolism*; D004041:Dietary Fats / Q000008:administration & dosage / Q000378:metabolism; D004042:Dietary Fats, Unsaturated / Q000008:administration & dosage / Q000378:metabolism*; D005260:Female; D005526:Food, Formulated; D005951:Glucose Tolerance Test; D006801:Humans; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance; D008297:Male; D009765:Obesity / Q000097:blood / Q000178:diet therapy* / Q000378:metabolism; D015431:Weight Loss / Q000502:physiology
D001786:Blood Glucose; D004040:Dietary Carbohydrates; D004041:Dietary Fats; D004042:Dietary Fats, Unsaturated; D007328:Insulin