The effects of proteins and medium-chain fatty acids from milk on body composition, insulin sensitivity and blood pressure in abdominally obese adults.
To investigate whether intake of whey protein and butter naturally enriched in medium-chain fatty acids (MC-SFAs) (C6-C12) affected body composition, insulin sensitivity, blood pressure (BP) and plasma cholesterol concentrations.



A 12-week randomised, double-blinded, intervention study was completed in 52 abdominally obese adults. Subjects were assigned to one of four dietary supplementations: 63 g per day of milk fat with either high- (8.5 g per day) or low-MC-SFA (6.9 g per day) content combined with 60 g per day of whey or casein.We examined changes in the body composition by dual-energy X-ray absorption scan, insulin sensitivity using homoeostatic model assessment of insulin resistance (HOMA-IR) and Matsuda index, and diurnal BP and plasma cholesterol concentrations. Two-factor analysis of variance was used to examine the impact of MC-SFA content and protein type.



We observed that lean body mass increased by 981 g (95% confidence interval (CI): 248-1713; P=0.010) after high-MC-SFA compared with low-MC-SFA supplementation. Concomitantly, total body-fat percentage increased by 0.70 percentage points (95% CI: 0.10-1.31; P=0.024) after intake of low-MC-SFA butter compared with intake of high-MC-SFA butter. Both changes were independent of protein type (P=0.96 and P=0.99, respectively). We found no difference in HOMA-IR, Matsuda index, diurnal BP or plasma cholesterol concentrations related to MC-SFA content or protein type.



Enhanced intake of MC-SFA increased the lean body mass and caused a significantly lower total body-fat percentage compared with lower intake of MC-SFA. Consequently, the composition of dairy fat should be considered when evaluating the impact of dairy products on body composition.
Department of Endocrinology and Internal Medicine, Aarhus University Hospital, Aarhus, Denmark.
M
M
Bohl
Department of Endocrinology and Internal Medicine, Aarhus University Hospital, Aarhus, Denmark.|The Danish Diabetes Academy, Odense University Hospital, Odense, Denmark.
A
A
Bjørnshave
Department of Food Science, Aarhus University, Tjele, Denmark.
M K
MK
Larsen
Department of Endocrinology and Internal Medicine, Aarhus University Hospital, Aarhus, Denmark.
S
S
Gregersen
Department of Endocrinology and Internal Medicine, Aarhus University Hospital, Aarhus, Denmark.
K
K
Hermansen
D000328:Adult; D000368:Aged; D000818:Animals; D001794:Blood Pressure / Q000502:physiology; D001823:Body Composition / Q000502:physiology*; D002364:Caseins / Q000008:administration & dosage; D004038:Diet, Reducing / Q000379:methods; D019587:Dietary Supplements; D004311:Double-Blind Method; D005227:Fatty Acids / Q000008:administration & dosage*; D005260:Female; D006801:Humans; D007333:Insulin Resistance / Q000502:physiology; D008297:Male; D008875:Middle Aged; D008892:Milk / Q000737:chemistry*; D008894:Milk Proteins / Q000008:administration & dosage*; D056128:Obesity, Abdominal / Q000503:physiopathology / Q000628:therapy*; D000067816:Whey Proteins / Q000008:administration & dosage
D002364:Caseins; D005227:Fatty Acids; D008894:Milk Proteins; D000067816:Whey Proteins