P. K. Newby

Are Dietary Intakes and Eating Behaviors Related to Childhood Obesity? A Comprehensive Review of the Evidence

The purpose of this article is to comprehensively review studies that have examined the relation between diet and childhood obesity. The review specifically considers the roles of total energy intake and energy density; dietary composition; individual foods, food groups, and dietary patterns; beverage consumption; and eating behaviors. The paper also discusses methodological considerations and future research directions and concludes by summarizing the evidence presented and highlighting the ethical issues surrounding providing dietary advice.

Plant foods and plant-based diets: protective against childhood obesity?

The objective of this article is to review the epidemiologic literature examining the role of plant foods and plant-based diets in the prevention of childhood obesity. Available data suggest a protective effect of ready-to-eat cereal on risk of obesity, although prospective studies are still needed. Studies on fruit and vegetables; grains other than cereal; high-protein foods, including beans, legumes, and soy; fiber; and plant-based dietary patterns are inconsistent or generally null. The evidence base is limited, and most studies are fraught with methodologic limitations, including cross-sectional design, inadequate adjustment for potential confounders, and lack of consideration of reporting errors, stage of growth, and genetic influences. Well-designed prospective studies are needed. The lack of evidence showing an association between plant-based diets and childhood obesity does not mean that such diets should not be encouraged. Plant foods are highlighted in the Dietary Guidelines for Americans, and children do not meet the current recommendations for most plant foods. Although the advice to consume a plant-based, low-energy-dense diet is sound, ethical questions arise concerning the relatively high price of these diets in the United States and the way in which such diets are perceived in other parts of the world. Reducing the burden of childhood obesity, eliminating health disparities, and preventing the further spread of the disease around the globe will require not only policy interventions to ensure that plant foods are affordable and accessible to children of all income levels but also awareness of sociocultural norms that affect consumption.

Diet quality and obesity in women: the Framingham Nutrition Studies.

Obesity affects one in three American adult women and is associated with overall mortality and major morbidities. A composite diet index to evaluate total diet quality may better assess the complex relationship between diet and obesity, providing insights for nutrition interventions. The purpose of the present investigation was to determine whether diet quality, defined according to the previously validated Framingham nutritional risk score (FNRS), was associated with the development of overweight or obesity in women. Over 16 years, we followed 590 normal-weight women (BMI < 25 kg/m2), aged 25 to 71 years, of the Framingham Offspring and Spouse Study who presented without CVD, cancer or diabetes at baseline. The nineteen-nutrient FNRS derived from mean ranks of nutrient intakes from 3 d dietary records was used to assess nutritional risk. The outcome was development of overweight or obesity (BMI > or = 25 kg/m2) during follow-up. In a stepwise multiple logistic regression model adjusted for age, physical activity and smoking status, the FNRS was directly related to overweight or obesity (P for trend = 0.009). Women with lower diet quality (i.e. higher nutritional risk scores) were significantly more likely to become overweight or obese (OR 1.76; 95 % CI 1.16, 2.69) compared with those with higher diet quality. Diet quality, assessed using a comprehensive composite nutritional risk score, predicted development of overweight or obesity. This finding suggests that overall diet quality be considered a key component in planning and implementing programmes for obesity risk reduction and treatment recommendations.

Diet Quality, Physical Activity, Smoking Status, and Weight Fluctuation Are Associated with Weight Change in Women and Men

The effect of diet quality on weight change, relative to other body weight determinants, is insufficiently understood. Furthermore, research on long-term weight change in U.S. adults is limited. We evaluated prospectively patterns and predictors of weight change in Framingham Offspring/Spouse (FOS) women and men (n = 1515) aged > or =30 y with BMI > or = 18.5 kg/m2 and without cardiovascular disease, diabetes, and cancer at baseline over a 16-y period. Diet quality was assessed using the validated Framingham Nutritional Risk Score. In women, older age (P < 0.0001) and physical activity (P < 0.05) were associated with lower weight gain. Diet quality interacted with former smoking status (P-interaction = 0.02); former smokers with lower diet quality gained an additional 5.2 kg compared with those with higher diet quality (multivariable-adjusted P-trend = 0.06). Among men, older age (P < 0.0001) and current smoking (P < 0.01) were associated with lower weight gain, and weight fluctuation (P < 0.01) and former smoking status (P < 0.0001) were associated with greater weight gain. Age was the strongest predictor of weight change in both women (partial R(2) = 11%) and men (partial R(2) = 8.6%). Normal- and overweight women gained more than obese women (P < 0.05) and younger adults gained more weight than older adults (P < 0.0001). Patterns and predictors of weight change differ by sex. Age in both sexes and physical activity among women as well as weight fluctuation and smoking status in men were stronger predictors of weight change than diet quality among FOS adults. Women who stopped smoking over follow-up and had poor diet quality gained the most weight. Preventive interventions need to be sex-specific and consider lifestyle factors.

A comparison of dietary patterns derived by cluster and principal components analysis in a UK cohort of children

Background/Objectives:The objective of this study was to identify dietary patterns in a cohort of 7-year-old children through cluster analysis, compare with patterns derived by principal components analysis (PCA), and investigate associations with sociodemographic variables.Subjects/Methods:The main caregivers in the Avon Longitudinal Study of Parents and Children (ALSPAC) recorded dietary intakes of their children (8279 subjects) using a 94-item food frequency questionnaire. Items were then collapsed into 57 food groups. Dietary patterns were identified using k-means cluster analysis and associations with sociodemographic variables examined using multinomial logistic regression. Clusters were compared with patterns previously derived using PCA.Results:Three distinct clusters were derived: Processed (4177 subjects), associated with higher consumption of processed foods and white bread, Plant-based (2065 subjects), characterized by higher consumption of fruit, vegetables and non-white bread, and Traditional British (2037 subjects), associated with higher consumption of meat, vegetables and full-fat milk. Membership of the Processed cluster was positively associated with girls, younger mothers, snacking and older siblings. Membership of the Plant-based cluster was associated with higher educated mothers and vegetarians. The Traditional British cluster was associated with council housing and younger siblings. The three clusters were similar to the three dietary patterns obtained through PCA; each principal component score being higher on average in the corresponding cluster.Conclusions:Both cluster analysis and PCA identified three dietary patterns very similar both in the foods associated with them and sociodemographic characteristics. Both methods are useful for deriving meaningful dietary patterns.

Race and Region Are Associated with Nutrient Intakes among Black and White Men in the United States

Stroke mortality rates and prevalence of several chronic diseases are higher in Southern populations and blacks in the US. This study examined the relationships of race (black, white) and region (Stroke Belt, Stroke Buckle, other) with selected nutrient intakes among black and white American men (n = 9229). The Block 98 FFQ assessed dietary intakes and multivariable linear regression analysis was used to examine whether race and region were associated with intakes of fiber, saturated fat, trans fat, sodium, potassium, magnesium, calcium, and cholesterol. Race and region were significant predictors of most nutrient intakes. Black men consumed 1.00% lower energy from saturated fat compared with white men [multivariable-adjusted β: 1.00% (95% CI = -0.88, -1.13)]. A significant interaction between race and region was detected for trans fat (P < 0.0001), where intake was significantly lower among black men compared with white men only in the Stroke Belt [multivariable-adjusted β: -0.21 (95% CI = -0.11, -0.31)]. Among black men, intakes of sodium, potassium, magnesium, and calcium were lower, whereas cholesterol was higher, compared with white men (P < 0.05 for all). Comparing regions, men in the Stroke Buckle had the lowest intakes of fiber, potassium, magnesium, and calcium compared with those in the Stroke Belt and other regions; men in both the Stroke Buckle and Stroke Belt had higher intakes of cholesterol compared with those in other regions (P < 0.005 for all). Given these observed differences in dietary intakes, more research is needed to understand if and how they play a role in the health disparities and chronic disease risks observed among racial groups and regions in the US.

Dietary Patterns Are Associated With Incident Stroke and Contribute to Excess Risk of Stroke in Black Americans

Background and Purpose— Black Americans and residents of the Southeastern United States are at increased risk of stroke. Diet is one of many potential factors proposed that might explain these racial and regional disparities. Methods— Between 2003 and 2007, the REasons for Geographic and Racial Differences in Stroke (REGARDS) cohort study enrolled 30 239 black and white Americans aged ≥45 years. Dietary patterns were derived using factor analysis and foods from food frequency data. Incident strokes were adjudicated using medical records by a team of physicians. Cox-proportional hazards models were used to examine risk of stroke. Results— During 5.7 years, 490 incident strokes were observed. In a multivariable-adjusted analysis, greater adherence to the plant-based pattern was associated with lower stroke risk (hazard ratio, 0.71; 95% confidence interval, 0.56–0.91; Ptrend=0.005). This association was attenuated after addition of income, education, total energy intake, smoking, and sedentary behavior. Participants with a higher adherence to the Southern pattern experienced a 39% increased risk of stroke (hazard ratio, 1.39; 95% confidence interval, 1.05, 1.84), with a significant (P=0.009) trend across quartiles. Including Southern pattern in the model mediated the black–white risk of stroke by 63%. Conclusions— These data suggest that adherence to a Southern style diet may increase the risk of stroke, whereas adherence to a more plant-based diet may reduce stroke risk. Given the consistency of finding a dietary effect on stroke risk across studies, discussing nutrition patterns during risk screening may be an important step in reducing stroke.

Milk Intakes Are Not Associated with Percent Body Fat in Children from Ages 10 to 13 Years

Epidemiologic studies report conflicting results for the relationship between milk intake and adiposity in children. We examined prospective and cross-sectional associations between milk intake and percent body fat among 2245 children from the Avon Longitudinal Study of Parents and Children. Cross-sectional analyses were performed at age 13 y between total, full-fat, and reduced-fat milk intake assessed using 3-d dietary records and body fat from DXA. Prospective analyses were conducted between milk intakes at age 10 y and body fat at 11 and 13 y. Models were adjusted for age, sex, height, physical activity, pubertal status, maternal BMI, maternal education, and intakes of total fat, sugar-sweetened beverages, 100% fruit juice, and ready-to-eat cereals; baseline BMI was added to prospective models. Subset analyses were performed for those with plausible dietary intakes. Mean milk consumption at 10 and 13 y was (mean ± SD) 0.90 ± 0.73 and 0.85 ± 0.78 servings/d [1 serving = 8 oz of milk (244 g of plain and 250 g flavored milk)], respectively. Cross-sectional results indicated an inverse association between full-fat milk intake and body fat [β = -0.47 (95% CI = -0.76, -0.19); P = 0.001]. Milk intake at age 10 y was inversely associated with body fat at 11 y [β = -0.16 g/d (95%CI = -0.28, -0.04); P = 0.01], but not among those with plausible dietary intakes, suggesting that this association was influenced by dietary measurement errors. Milk intake was not associated with body fat at age 13 y after adjustment. Although our prospective results corroborate other findings of a null associations between milk intake and adiposity, our inconsistent findings across analyses suggest further investigation is needed to clarify the relation, and accounting for dietary reporting errors is an important consideration.

Early anthropometric measures and reproductive factors as predictors of body mass index and obesity among older women

OBJECTIVE:To examine whether early anthropometric measures and reproductive factors were associated with body mass index (BMI), overweight, and obesity.DESIGN:Cross-sectional, observational study.SUBJECTS:In all, 18 109 healthy women who participated in the Swedish Mammography Cohort aged 49–83 y.MEASUREMENTS:Early anthropometric (birthweight and body shape at age 10 y) and reproductive (age at menarche, age at the birth of the first child, and parity) variables were our predictors and current BMI, overweight (BMI 25–29.99 kg/m2), and obesity (BMI ≥30 kg/m2) were our outcomes.RESULTS:In multivariate-adjusted polytomous logistic regression analysis, risk of overweight and obesity increased with increasing body shape at age 10 y and decreased with increasing age at menarche and age at first birth (P for trend <0.0001). A U-shaped relation with birthweight was observed. In our tests for effect modification of the relation with overweight/obesity (ow/ob; BMI ≥25 kg/m2), we detected significant interactions between body shape at 10 y and age (P<0.0001); body shape at 10 y and physical activity (P<0.0001); age at first birth and smoking (P=0.02); and parity and physical activity (P=0.004). The increased risk of ow/ob among women who reported a larger childhood body shape was reduced as women moved from the lowest to highest quartile of physical activity in adulthood. Likewise, the increasing risk of ow/ob among women with greater parity was reduced with increased physical activity.CONCLUSION:Early anthropometric measures and reproductive factors are significantly associated with BMI, overweight, and obesity among older women. The effects of childhood body weight, age at first birth, and parity may be modified by adult lifestyle choices, as well as age.

Longitudinal comparisons of dietary patterns derived by cluster analysis in 7- to 13-year-old children

Little is known about changes in dietary patterns over time. The present study aims to derive dietary patterns using cluster analysis at three ages in children and track these patterns over time. In all, 3 d diet diaries were completed for children from the Avon Longitudinal Study of Parents and Children at 7, 10 and 13 years. Children were grouped based on the similarities between average weight consumed (g/d) of sixty-two food groups using k-means cluster analysis. A total of four clusters were obtained at each age, with very similar patterns being described at each time point: Processed (high consumption of processed foods, chips and soft drinks), Healthy (high consumption of high-fibre bread, fruit, vegetables and water), Traditional (high consumption of meat, potatoes and vegetables) and Packed Lunch (high consumption of white bread, sandwich fillings and snacks). The number of children remaining in the same cluster at different ages was reasonably high: 50 and 43% of children in the Healthy and Processed clusters, respectively, at age 7 years were in the same clusters at age 13 years. Maternal education was the strongest predictor of remaining in the Healthy cluster at each time point – children whose mothers had the highest level of education were nine times more likely to remain in that cluster compared to those with the lowest. Cluster analysis provides a simple way of examining changes in dietary patterns over time, and similar underlying patterns of diet at two ages during late childhood, that persisted through to early adolescence.