Maya Vadiveloo

Consumer purchasing patterns in response to calorie labeling legislation in New York City

BackgroundObesity is a major public health threat and policies aimed at curbing this epidemic are emerging. National calorie labeling legislation is forthcoming and requires rigorous evaluation to examine its impact on consumers. The purpose of this study was to examine whether point-of-purchase calorie labels in New York City (NYC) chain restaurants affected food purchasing patterns in a sample of lower income adults in NYC and Newark, NJ.MethodsThis study utilized a difference-in-difference design to survey 1,170 adult patrons of four popular chain restaurants in NYC and Newark, NJ (which did not introduce labeling) before and after calorie labeling was implemented in NYC. Receipt data were collected and analyzed to examine food and beverage purchases and frequency of fast food consumption. Descriptive statistics were generated, and linear and logistic regression, difference-in-difference analysis, and predicted probabilities were used to analyze the data.ResultsA difference-in-difference analysis revealed no significant favorable differences and some unfavorable differences in food purchasing patterns and frequency of fast food consumption between adult patrons of fast food restaurants in NYC and Newark, NJ. Adults in NYC who reported noticing and using the calorie labels consumed fast food less frequently compared to adults who did not notice the labels (4.9 vs. 6.6 meals per week, p <0.05).ConclusionWhile no favorable differences in purchasing as a result of labeling were noted, self-reported use of calorie labels was associated with some favorable behavioral patterns in a subset of adults in NYC. However, overall impact of the legislation may be limited. More research is needed to understand the most effective way to deliver calorie information to consumers.

Lifestyle, Anthropometric, and Obesity-Related Physiologic Determinants of Insulin-like Growth Factor-1 in the Third National Health and Nutrition Examination Survey (1988–1994)

PURPOSE Epidemiologic studies suggest that insulin-like growth factor-1 (IGF-1) is associated with obesity and, more recently, cancer. This study investigates multiple lifestyle, physiologic, and anthropometric determinants of circulating IGF-1 concentrations. METHODS Nationally representative data were used from the cross-sectional Third National Health and Nutrition Examination (NHANES III, 1988-1994) survey, which measured IGF-1 concentrations in blood, from a subsample of participants who were examined in the morning. After exclusion of persons with missing data, 6,058 men and women 20 years of age or older were included in the study. RESULTS The mean IGF-1 concentrations were 260 ng/mL in the entire population and were higher among men as compared with women (278.8 vs. 241.3 ng/mL; p<0.0001). IGF-1 decreased with increasing age (p<0.0001), body mass index (p<0.0001), and waist circumference (p<0.0001). Individuals with metabolic syndrome had lower IGF-1 concentrations after adjustment for covariates (p=0.0008). IGF-1 was inversely associated with increasing number of metabolic syndrome abnormalities (p=0.0008). All associations were stronger among women compared with men except across concentrations of glucose. IGF-1 concentrations did not vary by any other lifestyle or physiologic factors. CONCLUSIONS Age, adiposity, hyperglycemia, and metabolic syndrome influenced circulating IGF-1 concentrations. Diet and physical activity had no impact on IGF-1 in this nationally representative population.

Relationship between plasma carotenoids and prostate cancer

Abstract: Carotenoids, particularly lycopene, are thought to decrease prostate cancer risk, but the relationship between plasma carotenoid concentrations and risk in various populations has not been well characterized. Comparing 118 non-Hispanic Caucasian men mainly from southeast Texas with nonmetastatic prostate cancer with 52 healthy men from the same area, we conducted a case-control analysis evaluating associations between risk and plasma levels of total carotenoids, β-cryptoxanthin, α- and trans-β-carotene, lutein and zeaxanthin, total lycopenes, trans-lycopene, total cis-lycopenes, and cis-lycopene isoforms 1, 2, 3, and 5. Risk for men with high plasma levels of α-carotene, trans-β-carotene, β-cryptoxanthin, and lutein and zeaxanthin was less than half that for those with lower levels. In contrast, we observed no significant associations for total lycopenes, all-trans-lycopene, and cis-lycopene isomer peaks 2, 3, and 5, although high levels of cis-lycopene isomer peak 1 were inversely associated with risk. Analysis of men with aggressive disease (Gleason scores of ≥7, n= 88) vs. less aggressive cases (Gleason scores of <7, n = 30) failed to reveal significant associations between carotenoid levels and the risk of diagnosis with aggressive disease. These findings suggest that, in these men, higher circulating levels of α-cryptoxanthin, α-carotene, trans-β-carotene, and lutein and zeaxanthin may contribute to lower prostate cancer risk but not to disease progression.

Trends in dietary fat and high-fat food intakes from 1991 to 2008 in the Framingham Heart Study participants.

Few longitudinal studies carried out in US adults have evaluated long-term dietary fat intakes and compared them with the national recommendations during the two-decade period when the prevalence of obesity and insulin resistance increased substantively. In the present study, we examined trends in the intakes of dietary fats and rich dietary sources of fats in the Framingham Heart Study Offspring Cohort over a 17-year period. The cohort was established in 1971-75 with follow-up examinations being conducted approximately every 4 years. Dietary data were collected using a semi-quantitative FFQ beginning in 1991 (exam 5). We included 2732 adults aged ≥ 25 years with complete dietary data in at least three examinations from 1991 to 2008. Descriptive statistics were generated using SAS version 9.3, and a repeated-measures model was used to examine trends in macronutrient and food intakes using R. Over the 17 years of follow-up, the percentage of energy derived from total fat and protein increased (27·3-29·8% of energy and 16·8-18·0% of energy, respectively) and that derived from carbohydrate decreased (51·0-46·8% of energy; P-trend < 0·001). Increases in the percentage of energy derived from all fat subtypes were observed, except for that derived from trans-fats, which decreased over time (P-trend < 0·001). Trends were similar between the sexes, although women exhibited a greater increase in the percentage of energy derived from saturated fat and less reduction in the percentage of energy derived from trans-fats (P interaction < 0·05). Trends in fat intake were similar across the BMI categories. The number of weekly servings of cheese, eggs, ice cream desserts, nuts, butter and sausages/processed meats increased, whereas the intake of milk, margarine, poultry, confectioneries, chips and breads decreased (P-trend < 0·001). In this cohort of predominantly Caucasian older adults, the percentage of energy derived from dietary fats increased over time, but it remained within the national recommendations of less than 35 % of total energy, on average.

Metabolic Dysregulation of the Insulin–Glucose Axis and Risk of Obesity-Related Cancers in the Framingham Heart Study-Offspring Cohort (1971–2008)

Background: Obesity-related dysregulation of the insulin–glucose axis is hypothesized in carcinogenesis. We studied impaired fasting glucose (IFG) and other markers of insulin–glucose metabolism in the Framingham Heart Study-Offspring Cohort, which uniquely tracks these markers and cancer >37 years. Methods: Participants were recruited between 1971 and 1975 and followed until 2008 (n = 4,615; mean age 66.8 years in 2008). Serum glucose, insulin, and hemoglobin A1c were determined from fasting blood in quart-annual exams. Lifestyle and demographic information was self-reported. HRs and 95% confidence intervals (CI) of cancer risk were computed using time-dependent survival analysis (SASv9.3), while accounting for temporal changes for relevant variables. Results: We identified 787 obesity-related cancers, including 136 colorectal, 217 breast, and 219 prostate cancers. Absence versus presence of IFG 10 to 20 years and 20+ years before the event or last follow-up was associated with 44% (95% CI, 1.15–1.79) and 57% (95% CI, 1.17–2.11) increased risk of obesity-related cancers, respectively. When time-dependent variables were used, after adjusting for age, sex, smoking, alcohol, and body mass index, IFG was associated with a 27% increased risk of obesity-related cancer (HR = 1.27; CI, 1.1–1.5). Associations were stronger in smokers (HR = 1.41; CI, 1.13–1.76). Increased risk was noted among persons with higher insulin (HR = 1.47; CI, 1.15–1.88) and hemoglobin A1c (HR = 1.54; CI, 1.13–2.10) for the highest (≥5.73%) versus lowest (≤5.25%) category. A >2-fold increase in colorectal cancer risk was observed for all blood biomarkers of insulin–glucose metabolism, particularly with earlier IFG exposure. Nonsignificant increased risk of breast and prostate cancer was observed for blood biomarkers. Conclusions: Earlier IFG exposure (>10 years before) increased obesity-related cancer risk, particularly for colorectal cancer. Impact: Our study explicitly recognizes the importance of prolonged IFG exposure in identifying links between glucose dysregulation and obesity-related cancers. Cancer Epidemiol Biomarkers Prev; 22(10); 1825–36. ©2013 AACR.

Dietary Variety Is Inversely Associated with Body Adiposity among US Adults Using a Novel Food Diversity Index

BACKGROUND Consuming a variety (vs. monotony) of energy-poor, nutrient-dense foods may help individuals adhere to dietary patterns favorably associated with weight control. OBJECTIVE The objective of this study was to examine whether greater healthful food variety quantified using the US Healthy Food Diversity (HFD) index favorably influenced body adiposity. METHODS Men and nonpregnant, nonlactating women aged ≥20 y with two 24-h recalls from the cross-sectional NHANES 2003-2006 (n = 7470) were included in this study. Dietary recalls were merged with the MyPyramid Equivalent database to generate the US HFD index, which ranges from 0 to ∼1, with higher scores indicative of diets with a higher number and proportion of healthful foods. Multiple indicators of adiposity including BMI, waist-to-height ratio, android-to-gynoid fat ratio, fat mass index (FMI), and percentage body fat were assessed across US HFD index quintiles. ORs and 95% CIs were computed with use of multivariable logistic regression (SAS v. 9.3). RESULTS The US HFD index was inversely associated with most adiposity indicators in both sexes. After multivariable adjustment, the odds of obesity, android-to-gynoid ratio >1, and high FMI were 31-55% lower (P-trend < 0.01) among women in quintile 5 vs. quintile 1 of the US HFD index. Among men, the odds of obesity, waist-to-height ratio ≥0.5, and android-to-gynoid ratio >1 were 40-48% lower (P-trend ≤ 0.01) in quintile 5 vs. quintile 1 of the US HFD index. CONCLUSIONS Higher US HFD index values were inversely associated with indicators of body adiposity in both sexes, indicating that greater healthful food variety may protect against excess adiposity. This study explicitly recognizes the potential benefits of dietary variety in obesity management and provides the foundation to support its ongoing evaluation.

Greater Healthful Food Variety as Measured by the US Healthy Food Diversity Index Is Associated with Lower Odds of Metabolic Syndrome and its Components in US Adults

BACKGROUND Consuming a wider variety of nutrient-dense foods may promote adherence to healthful dietary patterns, leading to improved dietary quality and enhanced metabolic health. OBJECTIVE We used the US Healthy Food Diversity (HFD) index to simultaneously measure dietary variety, quality, and proportionality, hypothesizing a priori that race/ethnicity may moderate associations between diet and health. METHODS A representative sample of adults (n = 7470) aged 20+ y with two 24-h recalls and complete outcome data from the cross-sectional NHANES 2003-2006 were selected. US HFD values were generated using a previously validated equation with a theoretical range from 0 to nearly 1, with higher scores indicative of more varied diets with a higher proportion of healthful food groups. Metabolic syndrome (MetS) was defined using the most recent harmonized definition. Survey-weighted multivariable linear and logistic regression, adjusted for demographic factors, smoking, energy, screen time, and leisure activity, were used to compute means and ORs (95% CIs). RESULTS Adults in the third vs. first US HFD tertile had 21% lower odds of MetS [OR (95% CI): 0.79 (0.64, 0.98)] as well as lower odds of hypertension [0.83 (0.70, 0.995] and elevated waist circumference [0.75 (0.66, 0.86] after multivariable adjustment (P-trend < 0.05). The age- and sex-adjusted odds of low serum HDL cholesterol and impaired fasting plasma glucose (P-trend < 0.05) were lower in the highest vs. lowest US HFD tertile but attenuated with multivariable adjustment (P = 0.06 and 0.22, respectively). Notably, the US HFD index was only protective against adiposity among non-Hispanic white (NHW) and non-Hispanic black (NHB) adults, and MetS associations were driven by NHW adults. No associations were observed among Hispanic adults for any MetS components. CONCLUSIONS Greater healthful food variety was associated with lower odds of MetS and some MetS components in the total population, NHW adults, and NHB adults. This study provides preliminary evidence that healthful food diversity may protect against MetS and highlights the need for longitudinal and experimental research.

Associations between dietary variety and measures of body adiposity: a systematic review of epidemiological studies.

Dietary variety is positively correlated with energy intake in most studies. However, the associations between dietary variety and measures of body adiposity are inconsistent in the literature, which limits the development of clear national nutrition recommendations regarding dietary variety. In the present systematic review, we critically evaluate the associations between dietary variety and measures of body adiposity among healthy adults within the existing literature. We conducted a systematic search of the MEDLINE and Web of Science databases in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement to examine these associations. We identified twenty-six studies in total that investigated the associations between dietary variety and body adiposity measures. Total variety was non-significantly associated with body adiposity in most studies, while variety in recommended foods was either inversely associated (six out of ten studies) or non-significantly associated (three out of ten studies) with body adiposity. Conversely, variety in non-recommended foods (i.e. sources of added sugars and solid fats) increased the likelihood of excess adiposity in most studies (six out of nine studies). Definitions and measurement of dietary variety were inconsistent across studies and contributed to some of the discrepancies noted in the literature. In conclusion, among the studies that met the inclusion criteria for the present review, dietary variety was inconsistently associated with body adiposity in diverse populations. Using consistent and specific definitions of dietary variety may help provide further insight into the associations between dietary variety and excess adiposity before definitive public health messages are ma

Dietary Variety: An Overlooked Strategy for Obesity and Chronic Disease Control

Introduction The increased variety of energy-dense foods available in the U.S. has been implicated in the current obesity epidemic because greater food variety can amplify the pleasure associated with eating. Accordingly, U.S. public health recommendations regarding dietary variety have been tempered recently to accommodate changing food landscapes. In fact, limiting dietary variety has been recently explored as a strategy for promoting weight loss. Despite the presumed risks of promoting variety and expected benefits of limiting variety in some categories, little consensus exists in the epidemiologic evidence to support this recommendation. Moreover, as recommendations to consume a variety of foods from all food groups have been deemphasized within the Dietary Guidelines for Americans (DGA), insufficient research has evaluated using variety as a behavioral strategy to promote long-term adherence to diet patterns favorably associated with weight control and chronic disease. Given the large proportion of U.S. adults who insufficiently consume nutrient-dense, plant-based foods, rigorous evaluation of any strategy potentially able to shift individuals and populations toward healthier eating patterns they enjoy is worth considering. The purpose of the present commentary is to highlight existing research that supports a role for dietary variety for weight control and to consider the clinical and public health policy applications of this research going forward.

Greater Healthful Dietary Variety Is Associated with Greater 2-Year Changes in Weight and Adiposity in the Preventing Overweight Using Novel Dietary Strategies (POUNDS Lost) Trial

BACKGROUND Greater healthful dietary variety has been inversely associated with body adiposity cross-sectionally; however, it remains unknown whether it can improve long-term weight loss. OBJECTIVE This study prospectively examined associations between healthful dietary variety and short-term (6 mo) and long-term (2 y) changes in adiposity in the Preventing Overweight Using Novel Dietary Strategies (POUNDS Lost) weight-loss trial completed in 2007. METHODS Healthful dietary variety was assessed from 24-h recalls with the use of the US Healthy Food Diversity index among participants aged 30-70 y with overweight/obesity (n = 367). Changes in the index between baseline and 6 mo were divided into tertiles representing reduced (T1), stable (T2), or increased variety (T3). Body weight and waist circumference (WC) were measured every 6 mo, and the percentage of body fat and trunk fat were measured at 6 mo and 2 y. Associations between changes in variety and short-term and long-term changes in adiposity were analyzed by use of multivariable-adjusted generalized linear models and repeated-measures ANOVA. RESULTS Regardless of dietary arm, T3 compared with T2 was associated with greater reduction in weight (-8.6 compared with -6.7 kg), WC (-9.1 compared with -6.1 cm), and body fat at 6 mo (β = -4.61 kg, P < 0.05). At 2 y, individuals in T3 compared with those in T2 or T1 maintained greater weight loss [-4.0 (T3) compared with -1.8 kg (T2 and T1), P = 0.02] and WC reduction [-5.4 (T3) compared with -3.0 (T2) and -2.9 cm (T1), P = 0.01]. Total body fat and trunk fat reductions were similarly greater in T3 than in T2. CONCLUSIONS Increasing healthful food variety in energy-restricted diets may improve sustained reductions in weight and adiposity among adults with overweight or obesity on weight-loss regimens. This trial is registered at clinicaltrials.gov as NCT00072995.