Search for a command to run...
The Coronary Artery Risk Development in Young Adults (CADIA) study of young overweight adults, black and white, demonstrated that dietary patterns characterised by increased dairy consumption had an inverse association with insulin resistance in their study population. The inclusion of low or non-fat dairy products, which provide additional calcium in the diet, may promote increased weight loss and improve insulin resistance. Therefore, supplementing dairy products to obese subjects on a caloric-restricted diet may be a useful strategy to enhance weight loss and improve insulin resistance. The study assesses dairy Calcium supplementation and its effects on body Fat, plasma leptin and glucose levels in obese postmenopausal women. This prospective randomised study of 3 months, parallel trial on the effect of non-fat / low-fat dairy calcium combined with energy restriction in overweight/obese postmenopausal women. The study therefore tested the short-term effects of supplementing 56 overweight or obese (body mass index [BMI] >26 kg/m2) post menopausal women on a caloric-restricted diet (1,400 kilocalories [kcal]) with two levels of dairy as yoghurt on body composition, blood insulin, leptin and glucose concentration. The group consuming four supplemented dairy servings (DS-4) was provided ~1400 mg Ca/day, and the group consuming two supplemented dairy servings (DS-2) were provided ~800 mg Ca/day. Over the 3-months daily energy intake averaged 51% carbohydrate, 20.7% of protein and 27.6% of fat for both groups. At 3 months, the DS-4 group demonstrated decreased weight (87.7 to 86.2 kg, P=0.001), BMI (33.5 to 32.8 kg/m2, P < 0.001), total fat (36.1 to 34.7 kg, P<0.001), and trunk fat (18.3 to 17.6 kg, P < 0.001). There were non-significant decreases in plasma glucose (74.7 to 71.1 mg/dl, P=0.494), leptin (32.5 to 31.3 µg/L, P=0.231) and insulin. For the DS-2 group, there was decreased weight (86.4 to 84.4 kg, p<0.02), BMI (32.5 to 31.8 kg/m2, P=0.002), total fat (37.3 to 35.4 kg, P=0.003), trunk fat (17.1 to 16.5 kg, P = 0.27) and plasma leptin (27.8 to 25.2 µg/L, P=0.114). The DS-2 group demonstrated a surprising and significant increase in the fasting blood glucose, with a marginally significant increase in insulin resistance as measured by HOMA at 3 months. We observed a significant treatment effect between the DS-2 and DS-4 groups for: % energy from fat (P=0.025), % energy from protein (P=0.047) and leptin (P=0.044). The study report that in a population of obese/overweight postmenopausal women supplementing their diet with dairy which provided a total estimated calcium intake of ~1400 mg/day (i.e. DS-4) was successful in the reduction of trunk fat and plasma glucose, while dairy calcium and caloric restriction decreased weight, BMI, total body fat, and insulin and leptin during the intervention. In contrast, the supplemented group ingesting 800 mg/d of dairy calcium (i.e. DS-2) in combination with caloric restriction provided significant increases in plasma glucose and insulin resistance. Our study demonstrated the expected weight loss with caloric restriction, but a paradoxical increase in blood glucose levels with dairy supplementation provided to maintain baseline calcium intake. Increasing dairy supplementation abrogated this small increase in fasting blood glucose and insulin resistance. The benefits of dairy calcium supplementation may be dependent on both the dose and the context of overall caloric intake.