Diet composition, energy intake, and exercise in relation to body fat in men and women

This study examined the relationships among body fat, diet composition, energy intake, and exercise in adults. Male (n = 107) and female (n = 109) adults aged 18-71 y (36.6 +/- 1.0 y, means +/- SEM) were hydrostatically weighed to determine body fat (5.7-49.0% of total weight). Diet and exercise behaviors were determined by use of a questionnaire. As body fat increased, percent of energy intake derived from fat increased (p less than 0.001) whereas the percent from carbohydrate decreased (p less than 0.001). There was no relationship between energy intake and adiposity although leanness and exercise were related (p less than 0.001). When subgroups of lean and obese subjects were compared, the lean subjects derived approximately 29% of their energy from fat and 53% from carbohydrate vs 35% and 46%, respectively, for the obese subjects. No differences were found between groups for energy intake but the lean individuals exercised more often than did the obese individuals. These data suggest that diet composition may play as important a role in fat deposition as do energy intake and lack of exercise.     

The effect of dietary carbohydrate:fat ratio on energy intake by adult women

The effect of the dietary carbohydrate:fat (C:F) ratio on the spontaneous energy intake by healthy adults was investigated by comparing a high-carbohydrate diet (fat 24%, carbohydrate 58%, protein 18% of energy) and a high-fat diet (fat 47%, carbohydrate 35%, protein 18% of energy) in a 2 X 2 week cross-over design. Subjects were 22 healthy nuns in a Trappist convent with very regular activities. The diets consisted of combinations of liquid formula (75%) and standardized snacks (25%). The difference in C:F ratio was concealed: energy density, taste and appearance were similar. Energy consumption was recorded continuously. The mean daily energy intakes remained constant: 8276 kJ (1978 kcal). The difference in mean daily energy intake between diets was 73 kJ +/- 180 (SEM). Small changes in body weight were observed, but these are argued not to indicate definitive effects. It is concluded that changing the C:F ratio within commonly occurring ranges does not influence the spontaneous energy intake of healthy adults. The composition of the dietary fat was kept constant. Under practical conditions a change in the C:F ratio will also induce a change in the fatty acid composition of the diet, which might affect the energy intake regulation. Other experiments are required to see whether the C:F ratio can affect body composition or other physiological parameters in the long run.     

Impact of dietary fat content and fat oxidation on energy intake in humans

Three studies were performed to assess the effects of a high-fat diet and exercise-induced changes in fat oxidation on energy intake in humans. In the first study the short-term effect of a high-fat diet on spontaneous energy intake was investigated. The second study evaluated the long-term effect of a high-fat diet on adiposity and the third study evaluated the effect of exercise-induced changes in fat oxidation on short-term regulation of energy intake when subjects were consuming a high-fat diet. The results of these studies indicate that a high-fat diet induces a short-term hyperphagia, a high percentage of lipids in the usual diet is associated with a higher adiposity, and exercise may attenuate or amplify the high-fat, diet-induced hyperphagia, depending on the magnitude of the exercise-induced increase in fat oxidation.     

Use of fat-modified food products to change dietary fat intake of young people.

Food purchasing and preparation practices were modified in two boarding high schools to increase the polyunsaturated-to-saturated fat ratio (P/S) of the diet of students by changing food products rather than attempting to change eating behaviors. During years when fat-modified products were served, the P/S of males increased by 75 percent, versus a decrease of 6 percent during control years. For females, P/S increased by 53 percent during intervention years, versus an increase of 6 percent during control years.     

Stages of change and the intake of dietary fat in African-American women: improving stage assignment using the Eating Styles Questionnaire

OBJECTIVE: To develop an algorithm for determining the stage of change for dietary fat intake in African-American women. DESIGN: We examined the relationships between stage of change, dietary fat intake, and associated eating behaviors and developed an assessment tool for placing subjects in their appropriate stage of change. SUBJECTS: Working class and middle-income African-American women in Nashville, Tenn; 174 in study 1 and 208 in study 2. STATISTICAL ANALYSES: Fat and fiber intake by stage of change was examined using multivariate analysis of variance. Hierarchical cluster analysis was performed using Ward's method. RESULTS: A significant difference in fat intake was noted between women trying to change their intake and those not trying to change in study 1 (P < .001) and study 2 (P < .03). Of those trying to change, only 34% (study 1) and 9% (study 2) of subjects reported fat intakes below the Healthy People 2000 goal of 30% of energy from fat. In study 1, cluster analysis identified 14 groups of foods that significantly separated subjects into not trying, noncompliant, and compliant categories. Compliant subjects ate out less; ate fewer snack foods and less chicken, meat, and fat; and ate more fruits, vegetables, breakfast foods, and low-fat products. These results led to development of the Eating Styles Questionnaire (study 2), which facilitated more appropriate placement of the noncompliant group in stages of change for dietary fat intake. APPLICATIONS/CONCLUSIONS: These data support the stage construct of the Transtheoretical Model for dietary fat reduction in African-American women. Moreover, the Eating Styles Questionnaire (ESQ) can improve determination of stage of change for this group of women. The ESQ can be used to diagnose the eating styles that contribute to a high-fat intake and help in the design of interventions to lower fat intakes.     

Physical activity and energy intake selectively predict the waist-to-hip ratio in men but not in women.

BACKGROUND: The waist-to-hip ratio (WHR) has emerged as an important risk factor for several chronic diseases, but little quantitative information exists about its relation with energy intake and expenditure in men and women. OBJECTIVE: We examined the relative role of energy intake and physical activity as determinants of WHRs in men and women, after adjustment for body mass index (BMI) and other likely confounding factors. DESIGN: In the context of the European Prospective Investigation into Cancer and Nutrition (EPIC), 16433 women and 11520 men aged 30-82 y, apparently healthy and from all over Greece, were examined between 1994 and 1999. Anthropometric measurements were taken, a validated semiquantitative food-frequency questionnaire was administered, and time-weighted occupational and leisure activities were assessed. The WHR was regressed, separately for men and women, on energy intake and energy expenditure after age and BMI were controlled for. RESULTS: Results for women and men differed. In women, neither energy intake nor energy expenditure was associated with the WHR in any way other than that mediated through BMI. In contrast, in men, higher energy intakes and higher energy expenditures were associated significantly, and largely independently of BMI, with higher and lower WHRs, respectively. CONCLUSIONS: Because the WHR is an important predictor of several cardiovascular and other chronic diseases, documentation of a strong effect of physical activity on the WHR selectively in men may provide a partial explanation of how the effect of physical activity is mediated and why physical activity is more effective in men than in women in reducing disease risk.     

Serum leptin and total dietary energy intake: the INTERLIPID Study

Purpose

It has been hypothesized that leptin-induced appetite suppression is impaired in obese individuals, but little human evidence is available documenting this. We investigated relations between serum leptin and total energy intake using INTERLIPID/INTERMAP data on Japanese–Americans in Hawaii and Japanese in Japan.

Methods

Serum leptin and nutrient intakes were examined by standardized methods in men and women aged 40–59 years from two population samples, one Japanese–American in Hawaii (88 men, 94 women), the other Japanese in central Japan (123 men, 111 women). Multiple linear regression analyses stratified by BMI category (<25 kg/m², 25–29.9 kg/m², and ≥30 kg/m²) with adjustment for possible confounders were used to examine the relation between log-leptin and total dietary energy intake.

Results

In multivariate regression analyses, in those with BMI < 25 kg/m² and in those with BMI between 25 and 29.9 kg/m², log-leptin was not significantly related to total dietary energy intake; in those with BMI ≥ 30 kg/m², it was significantly inversely related to total dietary energy intake (P = 0.029), independent of body weight and physical activity. Physical activity score was significantly positively related to total dietary energy intake only in participants with BMI < 25 kg/m² (P < 0.001).

Conclusion

Leptin was significantly inversely associated with dietary energy intake in obese persons, but not in overweight and normal-weight persons.     

Is dietary counselling effective in increasing dietary calcium,protein and energy intake in patients with osteoporotic fractures? A randomized controlled clinical trial

To determine the feasibility of increasing the calcium, protein and calorie intake of osteoporotic fracture patients by repeated dietary counselling delivered by a dietitian, a randomized controlled trial was conducted. Among 189 patients presenting with osteoporotic fractures to an Orthopaedics and Traumatology Department of a large regional hospital, 98 patients were randomized to the intervention group and 91 were randomized to the control group (with usual care). Intervention group received three sessions of dietary counselling with tailored made recommendations over a period of 4 months, while the control group only received dietary assessment and pamphlets on the prevention of osteoporosis. Almost all subjects in both intervention and control groups had calcium intake below the recommended level of 1000 mg at baseline. Half and 60% of subjects in both groups had total energy and protein intake below recommended levels respectively. The mean weights of control and intervention groups at baseline were 51.5 and 50.9 kg respectively, while the body mass index (BMI) were 22.6 (kg m(-2)) and 22.6 (kg m(-2)) respectively. After dietary intervention, significant increase of intake was seen in calcium intake (P = 0.0095 by t-test) in the intervention group. No significant increase was seen in protein or calorie intake. No significant change was observed in the body weight or BMI although there was a positive trend in the intervention group for all these parameters. We concluded that there was general malnutrition in Chinese elderly who presented with osteoporotic fractures. Dietary calcium could be increased by repeated professional dietary counselling. Future studies with longer duration and more objective clinical outcomes will be helpful to further demonstrate the long-term effects of dietary intervention on osteoporosis and other chronic diseases.     

Testing the predictive power of the transtheoretical model of behavior change applied to dietary fat intake

This study evaluated how well predictions from the transtheoretical model (TTM) generalized from smoking to diet. Longitudinal data were used from a randomized control trial on reducing dietary fat consumption in adults (n =1207) recruited from primary care practices. Predictive power was evaluated by making a priori predictions of the magnitude of change expected in the TTM constructs of temptation, pros and cons, and 10 processes of change when an individual transitions between the stages of change. Generalizability was evaluated by testing predictions based on smoking data. Three sets of predictions were made for each stage: Precontemplation (PC), Contemplation (C) and Preparation (PR) based on stage transition categories of no progress, progress and regression determined by stage at baseline versus stage at the 12-month follow-up. Univariate analysis of variance between stage transition groups was used to calculate the effect size [omega squared (omega(2))]. For diet predictions based on diet data, there was a high degree of confirmation: 92%, 95% and 92% for PC, C and PR, respectively. For diet predictions based on smoking data, 77%, 79% and 85% were confirmed, respectively, suggesting a moderate degree of generalizability. This study revised effect size estimates for future theory testing on the TTM applied to dietary fat.     

乌鲁木齐市学龄儿童膳食能量与血脂水平调查

目的:了解肥胖儿童血脂水平及膳食热能摄入状况,为预防儿童青少年心血管疾病提供参考依据。方法:随机抽取乌鲁木齐市63名体重正常儿童与63名肥胖儿童进行1∶1配对研究,对两组儿童进行膳食调查和血脂检测。结果:肥胖组儿童蛋白质、脂肪及碳水化合物占总热能比例分别为15.0%,42.0%,41.4%,肥胖组儿童膳食总热能的摄入及膳食脂肪、蛋白质的摄入均高于体重正常组儿童,同时两组儿童都存在膳食营养不平衡的情况;肥胖组儿童的血清甘油三酯、总胆固醇、载脂蛋白B均高于体重正常儿童(P<0.01),高密度脂蛋白和载脂蛋白A1均低于体重正常儿童(P<0.01)。结论:肥胖儿童中普遍存在的高热能,高脂肪膳食模式,促进了血脂含量的增加,使其青春期和成年后患心血管疾病的风险增大。     

A simple score and questionnaire to measure group changes in dietary fat intake

BACKGROUND. A short 12-term questionnaire was designed to measure changes in the dietary intake of saturated and total fat among groups of people attending health promotion events. A simple score (the fat-habits score) derived from the questionnaire was compared with estimates of saturated and total fat intake (% total energy) estimated from a standard 180-item food frequency questionnaire of 105 children (less than 18 years) and 202 adults (greater than 18 years). RESULTS. The correlation coefficients for saturated fat intake and the fat-habits score were 0.60 (95% CI = 0.50 to 0.68) in adults and 0.54 (95% CI = 0.39 to 0.66) in children, and those for total fat and the fat-habits score were 0.46 (95% CI = 0.41 to 0.56) in adults and 0.40 (95% CI = 0.22 to 0.55) in children. Linear regression equations relating the fat-habits score to saturated and total fat were used to predict changes in fat intake in 12 children and 27 adults who completed both questionnaires 6 months apart. The differences between the predicted changes in saturated and total fat and the observed changes measured by the food frequency questionnaires were not significant (saturated fat: adults -0.3%, 95% CI = -1.3 to 0.7%; children -0.2%, 95% CI = -1.7 to 1.3%; total fat: adults -0.6%, 95% CI = -2.9 to 1.7%; children -0.4%, 95% CI = -2.8 to 2.0%). The study had a 90% power of detecting a difference between the predicted and the observed changes for saturated fat of greater than +/- 1.7% (adults) and +/- 2.5% (children), and for total fat of greater than +/- 3.9% (adults) and +/- 4.0% (children). Conclusion. Thus simple scores can be used to evaluate group changes in fat intake.     

Designing a quality assurance system for dietary data in a multicenter clinical trial: Women's Intervention Nutrition Study

Reliable dietary intake data are essential for determining outcomes in nutrition-related clinical trials. Nevertheless, systems for quality assurance of dietary intake data are often slighted in the design of such trials and not incorporated or monitored as the trials continue. The Women's Intervention Nutrition Study (WINS), a multicenter clinical trial investigating the effect of reduction of dietary fat intake together with adjuvant systemic therapy on recurrence rates in and survival of postmenopausal women with early stage, surgically treated, breast cancer, has developed a quality assurance system to minimize errors and to produce data that are complete and reliable. The system involves development of standardized procedures for data collection, a quality control program to evaluate the data collected, and continual monitoring and reevaluation. The WINS system is offered as a model for studies collecting dietary intake data, no matter how simple or complex the trial design.     

Effect of increasing fruit and vegetable intake by dietary intervention on nutritional biomarkers and attitudes to dietary change: a randomised trial

Purpose

Low fruit and vegetable consumption is linked with an increased risk of death from vascular disease and cancer. The benefit of eating fruits and vegetables is attributed in part to antioxidants, vitamins and phytochemicals. Whether increasing intake impacts on markers of disease remains to be established. This study investigates whether increasing daily intake of fruits, vegetables and juices from low (approx. 3 portions), to high intakes (approx. 8 portions) impacts on nutritional and clinical biomarkers. Barriers to achieving the recommended fruit and vegetable intakes are also investigated.

Method

In a randomised clinical trial, the participants [19 men and 26 women (39–58 years)] with low reported fruit, juice and vegetable intake (<3 portions/day) were randomised to consume either their usual diet or a diet supplemented with an additional 480 g of fruit and vegetables and fruit juice (300 ml) daily for 12 weeks. Nutritional biomarkers (vitamin C, carotenoids, B vitamins), antioxidant capacity and genomic stability were measured pre-intervention, at 4-, 8- and 12 weeks throughout the intervention. Samples were also taken post-intervention after a 6-week washout period. Glucose, homocysteine, lipids, blood pressure, weight and arterial stiffness were also measured. Intake of fruit, fruit juice and vegetables was reassessed 12 months after conducting the study and a questionnaire was developed to identify barriers to healthy eating.

Results

Intake increased significantly in the intervention group compared to controls, achieving 8.4 portions/day after 12 weeks. Plasma vitamin C (35%), folate (15%) and certain carotenoids [α-carotene (50%) and β-carotene (70%) and lutein/zeaxanthin (70%)] were significantly increased (P < 0.05) in the intervention group. There were no significant changes in antioxidant capacity, DNA damage and markers of vascular health. Barriers to achieving recommended intakes of fruits and vegetables measured 12 months after the intervention period were amount, inconvenience and cost.

Conclusion

While increasing fruit, juice and vegetable consumption increases circulating level of beneficial nutrients in healthy subjects, a 12-week intervention was not associated with effects on antioxidant status or lymphocyte DNA damage.

Trial registration

This trial was registered at Controlled-Trials.com; registration ISRCTN71368072.

     

Longitudinal nutrient intake patterns of US adolescent women: the Penn State Young Women's Health Study.

PURPOSE: To use longitudinal nutrient intake data to determine whether dietary patterns remain consistent (or "track") as U.S. females progress from age 12 to 18 years. METHODS: Three-day diet records were collected at regular intervals over 6 years from participants in the Penn State Young Women's Health Study. Eighty-one subjects remained in the cohort during the study period. Tracking in body weight, in dietary intake of fat, sugar, iron, vitamin C, and in a total dietary score (TDS) was assessed using quartile-ranking analysis, year-to-year Pearson correlation analysis, and longitudinal linear analysis. RESULTS: Rank analysis revealed that subjects maintained their relative quartile positions for body weight throughout the study period, and year-to-year correlation coefficients for this variable were .93-.94. In contrast, rank and correlation analyses showed that the subjects did not track strongly with respect to any nutrient variable. Age 12 to 18 years correlation coefficients ranged from r = .04 for fat intake to r = .15 for the TDS. In longitudinal linear models, slopes differed in direction and significance across the original quartiles for nutrient intake, indicating varying dietary trends over time within the study population. CONCLUSIONS: Nutrient intake patterns do not track strongly throughout adolescence among U.S. females.     

Development and evaluation of a short instrument to estimate usual dietary intake of percentage energy from fat

OBJECTIVE: To describe the data-based development of a short dietary assessment instrument, a 16-item screener; and to evaluate the performance of the screener, comparing its performance with a complete 120-item food frequency questionnaire (FFQ) in assessing percentage energy from fat intake. DESIGN: A subsample (n=404) of participants in the National Institutes of Health-AARP Diet and Health Study, who had completed an FFQ and two 24-hour dietary recalls, also completed the fat screener. Percentage energy from fat from the screener and from the FFQ were compared with estimated true usual intake using a measurement error model. RESULTS: For men, the mean percentage energy from fat estimates for the different methods were: recalls, 30.1%, screener, 29.9%; FFQ, 30.4%. For women, the results were: recalls, 31.3%, screener, 28.4%, FFQ, 30.0%. Estimated correlations between true intake and screener were 0.64 and 0.58 for men and women, respectively, and between true intake and FFQ were 0.67 for men and 0.72 for women. Estimated attenuation coefficients for the screener were 1.29 (men) and 0.98 (women) and for the FFQ were 0.56 (men) and 0.57 (women). CONCLUSIONS: The percentage energy from fat screener, when used in conjunction with external reference data, may be useful to compare mean intakes of fat for different population subgroups, and to examine relationships between fat intake and other factors.     

US Food and Drug Administration's Total Diet Study: dietary intake of perchlorate and iodine

The US Food and Drug Administration (FDA) has conducted the Total Diet Study (TDS) since 1961, which designed to monitor the US food supply for chemical contaminants, nutritional elements, and toxic elements. Recently, perchlorate was analyzed in TDS samples. Perchlorate is used as an oxidizing agent in rocket propellant, is found in other items (e.g., explosives, road flares, fireworks, and car airbags), occurs naturally in some fertilizers, and may be generated under certain climatic conditions. It has been detected in surface and groundwater and in food. Perchlorate at high (e.g., pharmacological) doses can interfere with iodide uptake into the thyroid gland, disrupting its function. The National Academy of Sciences (NAS) has identified that "the fetuses of pregnant women who might have hypothyroidism or iodide deficiency as the most sensitive population." This study reports on intake estimates of perchlorate and iodine, a precursor to iodide, using the analytical results from the TDS. Estimated average perchlorate and iodine daily intakes as well as the contribution of specific food groups to total intakes were estimated for 14 age/sex subgroups of the US population. The estimated smallest lower bound to the largest upper bound average perchlorate intakes by the 14 age/sex groups range from 0.08 to 0.39 micrograms per kilogram body weight per day (microg/kg bw/day), compared with the US Environmental Protection Agency (EPA) reference dose (RfD) of 0.7 microg/kg bw/day. Infants and children demonstrated the highest estimated intakes of perchlorate on a body weight basis. The estimated average iodine intakes by the 14 age/sex groups reveal a lower bound (ND=0) and upper bound (ND=LOD) range of average intakes from 138 to 353 microg/person/day. Estimated iodine intakes by infants 6-11 months exceed their adequate intake (AI), and intakes by children and adult age/sex groups exceed their relevant estimated average requirement (EAR).