Dietary changes among husbands of participants in a low-fat dietary intervention.

A dietary intervention delivered to one family member with a beneficial impact on other members could provide a cost-effective approach to public health dietary intervention programs. The Women's Health Trial (WHT) was a study in which women were randomized to be trained in adopting a low-fat diet or to continue their normal diet. The intervention women consumed 21% of total calories from fat versus 38% for control women at six months postrandomization. Husbands of women in the Seattle Clinical Center of the WHT were surveyed between 1985 and 1988 to determine whether and to what extent the husbands' diets changed at six months. Ninety-one intervention men and 162 control men, 79% of those eligible, participated. Intervention men reported an average weight loss of 2.4 pounds, compared to an average 0.7-lb loss among controls (P = .03). Based on self-reported change of specific foods, we found that intervention men more often reduced butter, margarine, eggs, and red meat over the six months than did control men (P less than .001). Based on nutrient consumption estimated by a food frequency questionnaire, intervention husbands consumed 34% of total calories from fat versus 36% for controls (P = 0.04). The number of meals shared with wives per week modified the effect of the intervention: among the intervention group, for every three meals shared, an accompanying one percentage point reduction in percentage of calories from fat occurred in the husband's diet. Thus, we suggest that dietary intervention programs attended by one spouse appear to exert a small beneficial effect on the other spouse.     

Very low-carbohydrate and low-fat diets affect fasting lipids and postprandial lipemia differently in overweight men

Hypoenergetic very low-carbohydrate and low-fat diets are both commonly used for short-term weight loss; however, few studies have directly compared their effect on blood lipids, with no studies to our knowledge comparing postprandial lipemia, an important independently identified cardiovascular risk factor. The primary purpose of this study was to compare the effects of a very low-carbohydrate and a low-fat diet on fasting blood lipids and postprandial lipemia in overweight men. In a balanced, randomized, crossover design, overweight men (n = 15; body fat >25%; BMI, 34 kg/m(2)) consumed 2 experimental diets for 2 consecutive 6-wk periods. One was a very low-carbohydrate (<10% energy as carbohydrate) diet and the other a low-fat (<30% energy as fat) diet. Blood was drawn from fasting subjects on separate days and an oral fat tolerance test was performed at baseline, after the very low-carbohydrate diet period, and after the low-fat diet period. Both diets had the same effect on serum total cholesterol, serum insulin, and homeostasis model analysis-insulin resistance (HOMA-IR). Neither diet affected serum HDL cholesterol (HDL-C) or oxidized LDL (oxLDL) concentrations. Serum LDL cholesterol (LDL-C) was reduced (P < 0.05) only by the low-fat diet (-18%). Fasting serum triacylglycerol (TAG), the TAG/HDL-C ratio, and glucose were significantly reduced only by the very low-carbohydrate diet (-44, -42, and -6%, respectively). Postprandial lipemia was significantly reduced when the men consumed both diets compared with baseline, but the reduction was significantly greater after intake of the very low-carbohydrate diet. Mean and peak LDL particle size increased only after the very low-carbohydrate diet. The short-term hypoenergetic low-fat diet was more effective at lowering serum LDL-C, but the very low-carbohydrate diet was more effective at improving characteristics of the metabolic syndrome as shown by a decrease in fasting serum TAG, the TAG/HDL-C ratio, postprandial lipemia, serum glucose, an increase in LDL particle size, and also greater weight loss (P < 0.05).     

High-fibre and low-fat diets in diabetes mellitus

1. Eight insulin-dependent and eight insulin-independent diabetic patients and twenty-eight non-diabetic essential hypertensive patients were given a high-fibre, high-unrefined carbohydrate and low-fat diet for 3 months duration. 2. The effects of this dietary regimen on the patients' fasting blood glucose, hypoglycaemic therapy and weight was observed. 3. Fasting lipid profiles were obtained before and after 3 months on the dietary regimen, and total serum lipids and lipoprotein fractions were analysed. 4. The insulin-dependent and insulin-independent diabetic patients showed a reduction in hypoglycaemic therapy, with no significant change in fasting blood glucose. The insulin-independent and non-diabetic groups both showed significant weight loss. 5. The three groups of patients showed a significant reduction in cardiovascular risk factors with either an elevation of high-density lipoprotein (HDL)-cholesterol or a fall in low-density lipoprotein (LDL)-cholesterol and a reduction in the total cholesterol: HDL-cholesterol value.     

Accuracy of women''s self-report of their last Pap smear.

We compared interview data and physician records on when women last had a Pap smear in a sample of 98 rural Black women. We found 20 per cent of women could not accurately report on whether a Pap smear had been done within three years (sensitivity = 0.95, specificity = 0.47). Source of gynecological care and perceived barriers to obtaining a Pap smear but not education were associated with inaccurate reports. Self-report may be a misleading measure of Pap smear screening in comparable groups of women.     

Prospective, randomized, controlled comparison of the effects of low-fat and low-fat plus high-fiber diets on serum lipid concentrations.

Previous studies examining the hypocholesterolemic effects of high-soluble-fiber diets have not been designed to control for dietary fat intake. Serum cholesterol reductions may therefore be accounted for by differences in consumption of fat. Moderately hypercholesterolemic, nonobese, Caucasian men and women, 30-50 y old were randomly assigned to low-fat, low-fat plus high-fiber, or usual-diet groups and followed for 12 mo. At 12 mo the high-fiber group consumed significantly more soluble fiber than both the low-fat and usual-diet groups (P = 0.0063 and P = 0.0001); the high-fiber group did not differ from the low-fat group in quantity of dietary fat consumed. The high-fiber group experienced a greater average reduction (13%) in serum cholesterol than did the low-fat (9%) and usual-diet (7%) groups. After adjustment for relevant covariates, the reduction in the high-fiber group was significantly greater than that in the low-fat group (P = 0.0482). Supplementation with soluble fiber reduces serum cholesterol beyond the reduction observed with low-fat diet alone.     

Immunological effects of low-fat diets with and without weight loss

OBJECTIVE: The immunologic effects of isocaloric reduced- and low-fat diets and a voluntary calorie-restricted low-fat diet resulting in weight loss were compared to the immunologic effects of an average American diet in hyperlipidemic individuals. METHODS: Ten hyperlipidemic subjects were studied during three six-week weight maintenance phases: baseline (BL) [35% fat [14% saturated fat (SFA), 13% monounsaturated fat (MUFA), 8% polyunsaturated fat (PUFA)] and 147 mg cholesterol (C)/1000 kcal], reduced-fat (RF) [26% fat (4% SFA, 11% MUFA, 11% PUFA) and 45 mg C/1000 kcal], and low-fat (LF) [15% fat (5% SFA, 5% MUFA, 3% PUFA) and 35 mg C/1000 kcal] diets followed by 12-week, low-fat calorie reduced phase (LFCR). RESULTS: During the last phase, the subjects' weight significantly decreased (p = 0.005). Cholesterol levels were significantly reduced during all phases, compared to BL diet (p < 0.05). Delayed-type hypersensitivity (DTH) was assessed using Multi-test CMI. Maximum induration diameters were 22.7, 25.4, 30.5, 34.5 mm for BL, RF, LF and LFCR diets, respectively. Subjects on the LFCR diets had significantly higher DTH compared to the BL diet (p = 0.005). No significant effect of diet was observed on lymphocyte proliferation or interleukin (IL)-1, IL-2 and prostaglandin (PG) E(2) production. CONCLUSIONS: These data suggest that low-fat diets (15% energy), under conditions which result in weight loss, do not compromise and may enhance the immune response of middle-aged and elderly hyperlipidemic subjects. The results of this study provide support for the hypothesis that moderate caloric restriction in humans may have a beneficial effect on cell-mediated immunity such as those reported in calorie-restricted rodents.     

Promoting adherence to low-fat, low-cholesterol diets: review and recommendations

Evidence that lowering blood cholesterol levels reduces risk of coronary heart disease has prompted widespread recommendations that hyperlipidemic individuals undergo dietary therapy. However, the extent to which people can adopt and maintain diets to lower lipids is unclear. In our article, we review what is currently known regarding adherence to low-fat diets and present an approach to dietary counseling for lowering cholesterol that incorporates elements of behavioral self-management and social learning theory. We discuss specific recommendations for counseling hyperlipidemic patients based on the Dietary Alternatives Study. Recommendations include providing patients with an adequate knowledge base to make dietary changes, using goal setting and self-monitoring to help patients initiate dietary changes, enlisting support from the patient's family, and enhancing self-efficacy to promote long-term dietary maintenance.     

How energy policies affect public health.

The connection between energy policy and increased levels of respiratory and cardiopulmonary disease has become clearer in the past few years. People living in cities with high levels of pollution have a higher risk of mortality than those living in less polluted cities. The pollutants most directly linked to increased morbidity and mortality include ozone, particulates, carbon monoxide, sulfur dioxide, volatile organic compounds, and oxides of nitrogen. Energy-related emissions generate the vast majority of these polluting chemicals. Technologies to prevent pollution in the transportation, manufacturing, building, and utility sectors can significantly reduce these emissions while reducing the energy bills of consumers and businesses. In short, clean energy technologies represent a very cost-effective investment in public health. Some 72% of the Federal government''s investment in the research, development, and demonstration of pollution prevention technologies is made by the Department of Energy, with the largest share provided by the Office of Energy Efficiency and Renewable Energy. This article will examine the connections between air pollution and health problems and will discuss what the Department of Energy is doing to prevent air pollution now and in the future.     

Weight loss in women participating in a randomized trial of low-fat diets

We examined weight changes over 1 and 2 y in 303 women enrolled in a low-fat dietary-intervention trial. Participants were randomly assigned to an intervention group that received intensive instruction in maintaining a low-fat diet or to a control group. After 1 y intervention-group women had decreased fat intake by 45.3 g (from 39.2% to 21.6% energy from fat) and weight by 3.1 kg (all P less than 0.0001); control-group women decreased fat intake by 8.8 g (from 38.9% to 37.3% energy from fat) and weight by 0.4 kg. In both univariate analyses and multivariate models, weight loss was more strongly associated with change in percent energy from fat than with change in total energy intake. These data, which are consistent with both epidemiologic and clinical studies, suggest that body adiposity is a function both of energy balance and the proportion of energy derived from fat.     

Nutrition knowledge, attitudes and perceived norms as correlates of selecting low-fat diets

This report describes the development and evaluation of scalesthat assess nutrition knowledge, attitudes about diet and perceivednorms associated with selecting low-fat diets. Participantswere 97 women, aged 45–59, with a broad range of dietaryfat intakes. Usual dietary patterns were assessed with a foodfrequency questionnaire, 8 days of food diaries and an 18-itemquestionnaire on fat-related diet behavior. Participants completeda questionnaire with 125 items. A Q-sort, and item and factoranalyses were used to develop three knowledge, two attitudeand four norms scales. These scales had fair internal consistencyreliabilities (ranges were 0.53–0.73), and most were significantlyassociated with both per cent of energy from fat and fat-relateddiet behavior. Factors most strongly associated with low-fatdiets were related to perceived norms and knowledge about fatin foods. In multiple regression models, norms and knowledgecontributed significantly and independently to both measuresof diet behavior, while the variance explained by attitudeswas small. These findings support the inclusion of componentsthat enhance practical food knowledge and change dietary behaviornorms in nutrition education programs. These scales may alsobe useful tools, both to evaluate nutrition intervention programsand to develop hypotheses about dietary behavior which can betested empirically.     

A randomized trial comparing low-fat and low-carbohydrate diets matched for energy and protein

Several recent studies have found greater weight loss at 6 months among participants on a very-low-carbohydrate (VLC) weight-loss diet compared with a low-fat (LF) weight-loss diet. Because most of these studies were not matched for calories, it is not clear whether these results are caused by decreased energy intake or increased energy expenditure. It is hypothesized that several energy-consuming metabolic pathways are up-regulated during a VLC diet, leading to increased energy expenditure. The focus of this study was to investigate whether, when protein and energy are held constant, there is a significant difference in fat and weight loss when fat and carbohydrate are dramatically varied in the diet. The preliminary results presented in this paper are for the first four of six postmenopausal overweight or obese participants who followed, in random order, both a VLC and an LF diet for 6 weeks. Other outcome measures were serum lipids, glucose, and insulin, as well as dietary compliance and side effects. Our results showed no significant weight loss, lipid, serum insulin, or glucose differences between the two diets. Lipids were dramatically reduced on both diets, with a trend for greater triglyceride reduction on the VLC diet. Glucose levels were also reduced on both diets, with a trend for insulin reduction on the VLC diet. Compliance was excellent with both diets, and side effects were mild, although participants reported more food cravings and bad breath on the VLC diet and more burping and flatulence on the LF diet.