The effects of providing personalized dietary feedback. A semi-computerized approach.

There not only seems to be a trend for people to underestimate the dietary risks that they face, but it appears that this underestimation may be related to the difficulties they encounter when trying to assess their own dietary intake. A study (n = 118) examining the effects of providing people with information about their own dietary fat intake on their attitudes towards dietary change and their subsequent fat consumption is described. Participants in a group receiving feedback about their fat intake did not decrease their consumption of fat more than did those in a control group. No effects on subsequent fat consumption were observed in a group who had higher than average levels of fat consumption, higher perceived fat consumption than actual fat consumption and who received feedback information about their fat consumption. The results are discussed in relation to their implications for health promotion strategies that focus on the motivational effects of providing people with information about their fat consumption.

Serum lipid response to dietary cholesterol in subjects fed a low-fat, high-fiber diet.

To determine whether hyperresponse to dietary cholesterol occurs in individuals consuming a low-fat diet, a study was performed on 58 subjects whose plasma cholesterol had changed by greater than or equal to 5% when intakes of two and seven eggs per week were compared in a previous study. Here, the effect of eating nine, zero, and nine eggs per week was studied over 3 consecutive months. Plasma total, LDL, and HDL cholesterol did not differ significantly. There was no correlation between individuals' lipoprotein changes in this and the previous study. Consistent hyperresponse to moderate cholesterol intake is not apparent in people eating a low-fat, high-fiber diet. Reduction in dietary cholesterol below 400 mg/d produces no further substantial cholesterol lowering.

Effect of dietary cholesterol on plasma cholesterol concentration in subjects following reduced fat, high fibre diet.

One hundred and sixty eight subjects participated in a randomised crossover study to determine whether halving or doubling the present dietary cholesterol intake from eggs had any influence on blood cholesterol concentration in people following current dietary recommendations. During the first eight weeks all participants were advised to follow a reduced fat diet (26% total energy for hyperlipidaemic patients, 35% total energy for normolipidaemic volunteers) with an increased ratio of polyunsaturated to saturated fatty acids. This background diet was continued throughout the 16 week experimental period, during which participants ate either two or seven eggs a week. A small but significant increase in total cholesterol was seen after four weeks in the group eating seven eggs a week compared with that in the group eating two eggs a week, but this was no longer apparent after eight weeks. Previous studies suggesting that dietary cholesterol has a greater effect on the serum cholesterol concentration either have been carried out against a background of a higher fat intake or have contrasted extreme cholesterol intakes. A further reduction in dietary cholesterol seems to be unnecessary in those people who have already reduced their intake of saturated fat and increased the ratio of polyunsaturated to saturated fatty acids and fibre rich carbohydrate.

Acceptability of high-fibre diets in diabetic patients.

Twenty-five diabetic patients were selected from Oxford Diabetic Clinics to assess their dietary compliance (Group A). All had been taught to follow diets rich in dietary fibre in which carbohydrate provided 50% of total energy. The results were compared with those obtained previously from a similar group of patients (Group B) all of whom had been instructed to follow a diet in which carbohydrate provided 40% of total energy. The patients of Group A had a significantly greater intake of carbohydrate (45.1% vs 34.7% of total energy) and dietary fibre (33.1 g vs 18.7 g) and a lower intake of fat (33.5% vs 42.1% of total energy) than the patients of Group B. The results of dietary assessment obtained from a third group of patients (Group C), who had been advised to follow a high-fibre diet before the widespread availability of dietary teaching aids and recipe books, showed that carbohydrate and fat provided 37.5% and 41.0% of total energy, with a dietary fibre intake of 25.6 g. The results suggest that patients are willing and able to change their dietary habits towards a distribution of food constituents likely to improve diabetic control and reduce the risk of coronary heart disease when given enthusiastic instruction and support in diabetic clinics.

A high carbohydrate leguminous fibre diet improves all aspects of diabetic control.

In a randomised cross-over study 18 nondependent (NIDDM) and 9 insulin-dependent (IDDM) diabetics were put on to a high carbohydrate diet containing leguminous fibre (HL) for 6 weeks, and also a standard low carbohydrate diet (LC) for 6 weeks. During two identical 24 h metabolic profiles mean preprandial and mean 2 hour postprandial blood glucoses were significantly lower on HL in both groups, as were also several overall measures of diabetic control, including the degree of glycosuria. Total cholesterol was reduced significantly on HL in both groups, and the HDL/LDL cholesterol ratio increased significantly on HL in the NIDDM group. A diet high in complex carbohydrate and leguminous fibre improves all aspects of diabetic control, and continued use of a low carbohydrate diet no longer appears justified.