OBJECTIVE -To determine the effect of a high-protein (HP) weight loss diet compared with a lower-protein (LP) diet on fat and lean tissue and fasting and postprandial glucose and insulin concentrations.RESEARCH DESIGN AND METHODS -Replacing dietary protein for carbohydrate (CHO) during energy restriction and weight loss has been effective in sparing lean mass and improving insulin sensitivity in obese subjects but has not been tested in subjects with type 2 diabetes. We compared an HP diet (28% protein, 42% CHO, 28% fat [8% saturated fatty acids, 12% monounsaturated fatty acids, 5% polyunsaturated fatty acids]) with an LP diet (16% protein, 55% CHO, 26% fat [8% saturated fatty acids, 11% monounsaturated fatty acids, 5% polyunsaturated fatty acids]) in 54 obese men and women with type 2 diabetes during 8 weeks of energy restriction (1,600 kcal) and 4 weeks of energy balance. Body composition was determined by dual-energy X-ray absorptiometry at weeks 0 and 12.RESULTS -Overall, weight loss of 5.2 Ϯ 1.8 kg was achieved independently of diet composition. However, women on the HP diet lost significantly more total (5.3 vs. 2.8 kg, P ϭ 0.009) and abdominal (1.3 vs. 0.7 kg, P ϭ 0.006) fat compared with the women on the LP diet, whereas, in men, there was no difference in fat loss between diets (3.9 vs. 5.1 kg). Total lean mass decreased in all subjects independently of diet composition. LDL cholesterol reduction was significantly greater on the HP diet (5.7%) than on the LP diet (2.7%) (P Ͻ 0.01).CONCLUSIONS -Both dietary patterns resulted in improvements in the cardiovascular disease (CVD) risk profile as a consequence of weight loss. However, the greater reductions in total and abdominal fat mass in women and greater LDL cholesterol reduction observed in both sexes on the HP diet suggest that it is a valid diet choice for reducing CVD risk in type 2 diabetes. Diabetes Care 25:425-430, 2002T ype 2 diabetes is a major public health problem in the developed world (1). Although there is a strong genetic predisposition to the development of type 2 diabetes, lifestyle and dietary factors, particularly those that promote obesity, are contributors (2). Type 2 diabetes is characterized in most subjects by insulin resistance with inadequate insulin response to maintain normoglycemia (3). Insulin resistance occurs partly as a result of increased concentrations of circulating plasma free fatty acids, released from excess adipocytes in obesity, which compete with glucose for uptake in skeletal muscle (4). In addition, hormones such as resistin (5) and cytokines such as tumor necrosis factor-␣ (6) released from adipocytes may exacerbate insulin resistance. Because ϳ90% of people with type 2 diabetes are obese, weight loss is essential in management. The optimal diet for type 2 diabetes has been the focus of much research, and there remains no consensus on macronutrient composition apart from recommendations that saturated fats be kept low (7). Energy restriction alone significantly improves glucose control and the plasma lipid pro...

Objective: Visual analogue scales are widely used in appetite research, yet the validity of these scales to evaluate appetite and mood has not been assessed in older subjects. The aim of this study was to determine the relations between food intake and visual analogue scale (VAS) ratings of appetite and nonappetite sensations in healthy older and young subjects. Design: Retrospective combined analysis of four single-blind, randomised, controlled appetite studies. Setting: All studies were conducted in the University of Adelaide, Department of Medicine, Adelaide, Australia. Subjects: A total of 45 healthy young men (n ¼ 24) and women (n ¼ 21) aged 18-35 y and 45 healthy older men (n ¼ 24) and women (n ¼ 21) aged 65-85 y were recruited by advertisement. Interventions: Oral, intraduodenal or intravenous administration of treatments which suppressed food intake were compared to control. Up to 90 min after treatment, a test meal was offered and subjects ate freely for between 30 and 60 min. Perceptions were assessed by 100-mm visual analogue scales administered at regular intervals. Results: Food intake at the test meal was positively related to perceptions of hunger, drowsiness, and calmness at both baseline and premeal (r 40.16, Po0.05), and inversely related to premeal ratings of fullness (r4 0.2, Po0.05) in both older and young subjects. Food intake was related to VAS ratings at least as strongly, if not more so, in older as in young subjects. Conclusions: These observations (i) confirm that food intake is related to perceptions of hunger and fullness as assessed by VAS in healthy older and young subjects, and (ii) suggest that sensations, not obviously associated with appetite, including 'drowsiness' and 'calmness', are also associated with food intake.

Aims/hypothesis. This study compared the long-term weight loss and health outcomes at 1-year follow-up, after a 12-week intensive intervention consisting of two low-fat, weight-loss diets, which differed in protein content. Methods. We randomly assigned 66 obese patients (BMI: 27-40 kg/m 2 ) with Type 2 diabetes to either a low-protein (15% protein, 55% carbohydrate) or high-protein diet (30% protein, 40% carbohydrate) for 8 weeks of energy restriction (~6.7 MJ/day) and 4 weeks of energy balance. Subjects were asked to maintain the same dietary pattern for a further 12 months of follow-up. Results. The study was completed by 38 of the subjects, with equal dropouts in each group. At Week 64, weight reductions against baseline were −2.2±1.1 kg (low protein) and −3.7±1.0 kg (high protein), p<0.01, with no diet effect. Fat mass was not different from baseline in either group. At Week 12, both diets reduced systolic and diastolic blood pressure by 6 and 3 mm Hg respectively, but blood pressure increased more with weight regain during follow-up in the lowprotein group (p≤0.04). At Week 64, both diets significantly increased HDL cholesterol and lowered C-reactive protein concentrations. There was no difference in the urinary urea : creatinine ratio at baseline between the two groups, but this ratio increased at Week 12 (in the high-protein group only, p<0.001, diet effect), remaining stable during follow-up in both diets. Conclusions/interpretation. A high-protein weightreduction diet may in the long term have a more favourable cardiovascular risk profile than a lowprotein diet with similar weight reduction in people with Type 2 diabetes.