Nutritional adequacy of diets reported at baseline and during trial years 1-6 by the special intervention and usual care groups in the Multiple Risk Factor Intervention Trial

Effect of calcium supplementation on weight and fat loss in women

Data suggest that a diet deficient in calcium is associated with higher body weight and that augmenting calcium intake may reduce weight and fat gain or enhance loss. Our aim was to determine whether calcium supplementation during a weight loss intervention affects body fat or weight loss. Data were combined from three separate 25-wk randomized, double blind, placebo-controlled trials of 1000 mg/d calcium supplementation in 100 premenopausal and postmenopausal women. The primary outcome measures were change in body weight and fat mass adjusted for baseline values. There were no significant differences in body weight or fat mass change between the placebo and the calcium-supplemented groups in the pooled analysis (adjusted mean +/- SE; body weight, placebo -6.2 +/- 0.7 vs. Ca -7.0 +/- 0.7 kg; fat mass, placebo -4.5 +/- 0.6 vs. Ca -5.5 +/- 0.6 kg), and no significant interactions of calcium supplementation with menopausal/diet status. Analysis as separate trials also found no significant differences between the placebo and the calcium groups. Calcium supplementation did not significantly affect amount of weight or fat lost by women counseled to follow a moderately restricted diet for 25 wk. Nevertheless, the magnitude and direction of the differences for group means are consistent with a hypothesized small effect.

Relative validity of a diet history interview in an intervention trial manipulating dietary fat in the management of Type II diabetes mellitus

BACKGROUND

This study assesses the relative validity of a diet history interview in 56 free-living individuals with Type II diabetes mellitus.

METHODS

The diet history interview was compared to a 3-day food record in a 1-year dietary intervention trial. The plausibility of energy intake data was examined throughout the trial. Paired data were compared for differences and the presence of systematic error was determined by Bland Altman analysis. Changes in accuracy and responsiveness were assessed over time.

RESULTS

The proportion of underreporters was larger in the diet history at baseline. Underrecording with the food record was more common in subjects with BMIs > 30 kg/m(2). There was no difference between paired dietary data from the two methods; however, data on fatty acids failed to correlate. These correlations improved when outliers were removed. There was no evidence of a relationship between bias and mean intake of dietary variables. Accuracy of diet history measurement did not change during the trial for energy or macronutrients, but data on protein and monounsaturated fat were both affected by BMI. The diet history was more responsive than the food record to changes in monounsaturated fatty acid intake after 3 months, but this changed at the end of the trial.

CONCLUSION

The diet history provided good estimates of energy and macronutrient intakes in a sample group with Type II diabetes mellitus. However, energy intake data revealed a high prevalence of underreporting especially in people with higher BMIs.

Changes in the intake of vitamins and minerals by men and women with hyperlipidemia and overweight during dietetic treatment

OBJECTIVES

To assess the influence of a low-fat, low-energy diet on the intake of vitamins and minerals in patients with overweight and hyperlipidemia.

SETTING

Outpatient clinic for hyperlipidemia treatment.

SUBJECTS

A total of 134 subjects chosen from patients attending Outpatient Clinic of Metabolic Diseases.

INTERVENTIONS

Patients were assigned to a hypolipidemic, low-energy diet of 4.18-6.27 MJ/day (1000 or 1500 kcal/day), where fat provided less than 30% of energy, saturated fatty acids less than 10% of energy and daily supply of cholesterol was below 300 mg. Dietary assessment with the use of 3 days dietary records were performed at baseline and after 8 weeks of the diet.

RESULTS

The implementation of a low-fat, low-energy diet resulted in a decrease of the intake of nutrients assessed, statistically significant for phosphorus, magnesium, iron and vitamin B(1), B(2) and niacin in men and for iron in women. No marked and statistically significant reduction in the percentage of the RDA was found, except magnesium, thiamin and riboflavin in men and iron in women. Nutritional density was statistically improved for phosphorus, potassium, magnesium and vitamins E, C and B(6) in men and for all nutrients assessed in women.

CONCLUSIONS

In comparison with a habitual diet, the low-fat, low-energy diet did not cause any marked and statistically significant decrease in the intake of minerals and vitamins or in the adherence to the RDA, with the exception of magnesium, thiamin and riboflavin in men and iron in women.