Translating advice to eat more vegetables into practice: observations from a 12-month weight loss trial.

OBJECTIVES: This study aimed to identify the main vegetable sources of overweight participants during a 12-month randomised controlled trial for weight loss. METHODS: Secondary analysis using data from diet history interviews to determine changes to daily vegetable intake amounts and types throughout the trial at 0, 3 and 12 months. RESULTS: Pre-trial 77% participants consumed frozen vegetables. At baseline (n = 113, 85 F), participants reported 345 ± 170 (56-920) g/day vegetables increasing to 498 ± 180 (146-930) g/day at 3 months and remaining stable at 475 ± 169(170-1053) g/day by 12 months (p = 0.001). At baseline, 32 of 34 different vegetable categories were reported, mainly tomato (69.9 g/day) and, potato (58.2 g/day). After 3 months (n = 109), seven vegetables remained in the top 10 reported (contributing 72%). Tomato remained top ranked to 12 months. CONCLUSION: Following advice to consume more vegetables, consumption increased above the Australian Dietary recommendation of ~375 g/day. Tomatoes remained a mainstay regardless of the time of year, but choices changed with time. Frozen vegetables may be a feasible option.

Foods, nutrients or whole diets: effects of targeting fish and LCn3PUFA consumption in a 12mo weight loss trial.

BACKGROUND: There is some evidence in the literature that emphasising fish consumption may assist with weight loss. The aim was to assess the effects of advice to consume 2 fish meals per week in a weight loss diet. METHODS: A parallel randomised placebo-controlled trial was conducted in 118 obese Australian adults (mean BMI ± SD 31.3 ± 3.5 kg/m2; mean age ± SD 45 ± 10 y; 28% male). Participants received low calorie dietary advice+placebo (1 g olive oil; CONTROL), low calorie dietary advice emphasising fish+placebo (Fish), or low calorie dietary advice emphasising fish diet + LCn3PUFA supplements (Fish+S). Individualised advice targeted 2 MJ energy deficit (30%E fat, 45%E carbohydrate and 25%E protein) with or without two servings (180 g) fatty fish/wk. RESULTS: All groups lost weight at 12 months (CONTROL -4.5 kg vs. Fish -4.3 kg vs. Fish+S -3.3 kg; p<0.001) and percentage body fat ( CONTROL: -1.5% vs. Fish: -1.4% vs. Fish+S: -0.7%; p<0.001) but there were no significant differences between groups. Cardiovascular disease risk factors changed as expected from weight loss. CONCLUSIONS: Advice to consume 2 fish meals per week did not enhance the effects on weight loss of a healthy low calorie diet. TRIAL REGISTRATION: ACTRN12608000425392.

Effect of 6 weeks' consumption of ß-glucan-rich oat products on cholesterol levels in mildly hypercholesterolaemic overweight adults.

Several regulatory bodies have approved a health claim on the cholesterol-lowering effects of oat ß-glucan at levels of 3·0 g/d. The present study aimed to test whether 1·5 g/d ß-glucan provided as ready-to-eat oat flakes was as effective in lowering cholesterol as 3·0 g/d from oats porridge. A 6-week randomised controlled trial was conducted in eighty-seven mildly hypercholesterolaemic ( ≥ 5 mmol/l and < 7·5 mmol/l) men and women assigned to one of three diet arms (25 % energy (E%) protein; 45 E% carbohydrate; 30 E% fat, at energy requirements for weight maintenance): (1) minimal ß-glucan (control); (2) low-dose oat ß-glucan (1·5 g ß-glucan; oats low - OL) or (3) higher dose oat ß-glucan (3·0 g ß-glucan; oats high - OH). Changes in total cholesterol and LDL-cholesterol (LDL-C) from baseline were assessed using a linear mixed model and repeated-measures ANOVA, adjusted for weight change. Total cholesterol reduced significantly in all groups ( - 7·8 (sd 13·8) %, - 7·2 (sd 12·4) % and - 5·5 (sd 9·3) % in the OH, OL and control groups), as did LDL-C ( - 8·4 (sd 18·5) %, - 8·5 (sd 18·5) % and - 5·5 (sd 12·4) % in the OH, OL and control groups), but between-group differences were not significant. In responders only (n 60), ß-glucan groups had higher reductions in LDL-C ( - 18·3 (sd 11·1) % and - 18·1 (sd 9·2) % in the OH and OL groups) compared with controls ( - 11·7 (sd 7·9) %; P = 0·044). Intakes of oat ß-glucan were as effective at doses of 1·5 g/d compared with 3 g/d when provided in different food formats that delivered similar amounts of soluble ß-glucan.

Pork, beef and chicken have similar effects on acute satiety and hormonal markers of appetite.

The effects of three different meat-containing breakfast meals (pork, beef or chicken) on acute satiety and appetite regulatory hormones were compared using a within-subjects study design. Thirty fasting non-smoking pre-menopausal women attended a research centre on three test days to consume, a meat-containing meal matched in energy (kJ) and protein content, palatability, and appearance. No difference was found between meat groups for either energy intake or macronutrient profile of food consumed at a subsequent ad libitum buffet lunch, or over the rest of the day. Visual Analogue Scale (VAS) ratings for hunger and satiety over an 180 min period did not differ between test meals. After consumption of the test meals, a significant difference was found in PYY response between pork and chicken meals (P=0.027) but not for levels of CCK, ghrelin, insulin or glucose. This study positions pork, beef, and chicken as equal in their effect on satiety and release of appetite-related intestinal hormones and of insulin.

Cereal grains, legumes, and weight management: a comprehensive review of the scientific evidence.

There is strong evidence that a diet high in whole grains is associated with lower body mass index, smaller waist circumference, and reduced risk of being overweight; that a diet high in whole grains and legumes can help reduce weight gain; and that significant weight loss is achievable with energy-controlled diets that are high in cereals and legumes. There is weak evidence that high intakes of refined grains may cause small increases in waist circumference in women. There is no evidence that low-carbohydrate diets that restrict cereal intakes offer long-term advantages for sustained weight loss. There is insufficient evidence to make clear conclusions about the protective effect of legumes on weight.