Adam Drewnowski

Obesity, diets, and social inequalities

Obesity and type 2 diabetes follow a socioeconomic gradient. Highest rates are observed among groups with the lowest levels of education and income and in the most deprived areas. Inequitable access to healthy foods is one mechanism by which socioeconomic factors influence the diet and health of a population. As incomes drop, energy-dense foods that are nutrient poor become the best way to provide daily calories at an affordable cost. By contrast, nutrient-rich foods and high-quality diets not only cost more but are consumed by more affluent groups. This article discusses obesity as an economic phenomenon. Obesity is the toxic consequence of economic insecurity and a failing economic environment.

Sweet tooth reconsidered: Taste responsiveness in human obesity

Taste responses of normal-weight, obese, and formerly obese individuals for sucrose and fat containing stimuli were examined using a mathematical modelling technique known as the Response Surface Method. The subjects accurately rated intensities of sweetness, fatness, and creaminess of 20 different mixtures of milk, cream, and sugar, and no mixture phenomena or inter-group differences were observed. In contrast, hedonic taste responses varied across subject groups, and were affected differentially by the sucrose and lipid content of the stimuli. Normal-weight subjects optimally preferred stimuli containing 20% lipid and less than 10% sucrose. Obese subjects preferred high-fat stimuli (greater than 34% lipid) that contained less than 5% sucrose, while formerly obese subjects showed enhanced responsiveness to both sugar and fat. Hedonic responsiveness as measured by the optimal sugar/fat ratio was negatively correlated with the degree of overweight (body mass index: weight/height). We hypothesize that sensory preferences for dietary sugars and fats aren determined by body-weight status and may affect the patterns of food consumption.

Food preferences in human obesity: carbohydrates versus fats.

A large clinical sample of obese men and women were asked for a self-generated list of ten favorite foods. The lists were characterized by frequent instances of foods that are major nutrient sources of fat in the American diet. While obese men listed mainly protein/fat sources (meat dishes) among their favorite foods, obese women tended to list predominantly carbohydrate/fat sources (doughnuts, cookies, cake) and foods that were sweet. There was no evidence that selective preferences for a single macronutrient, carbohydrate, were a standard feature of human obesity. Rather, preferences for major nutrient sources of fat as opposed to carbohydrate may be a primary characteristic of human obesity syndromes.

Taste responses and preferences for sweet high-fat foods: Evidence for opioid involvement

Preferences and cravings for sweet high-fat foods observed among obese and bulimic patients may involve the endogenous opioid peptide system. The opioid antagonist naloxone, opioid agonist butorphanol, and saline placebo were administered by intravenous infusion to 14 female binge eaters and 12 normal-weight controls. Eight of the binge eaters were obese. During infusion, the subjects tasted 20 sugar/fat mixtures and were allowed to select and consume snack foods of varying sugar and fat content. Naloxone reduced taste preferences relative to baseline in both binge eaters and controls. Total caloric intake from snacks was significantly reduced by naloxone in binge eaters but not in controls. This reduction was most pronounced for sweet high-fat foods such as cookies or chocolate. No consistent effects on taste preferences or food intakes were observed with butorphanol. Endogenous opioid peptides may be involved in mediating taste responses and preferences for palatable foods, notably those rich in sugar and fat.

The Dietary Variety Score: Assessing Diet Quality in Healthy Young and Older Adults

OBJECTIVE To develop a new dietary variety score (DVS) and link it to other measures of diet quality, including a modified diet quality index (DQI). SUBJECTS The subjects were 24 healthy young (ages 20 to 30 years) and 24 healthy older (ages 60 to 75 years) adults, including 24 men and 24 women. Their dietary intake assessments were based on one 24-hour food recall interview and 14 consecutive days of food records. DESIGN AND MEASURES Energy and nutrient intakes were estimated using Nutritionist IV software. DVS was based on the cumulative number of different foods consumed over the 15-day period. DQI was a 5-point scale based on conformity with the key US dietary recommendations. Full score was awarded for diets deriving 30% or less of energy from fat, 10% or less of energy from saturated fat, more than 50% of energy from carbohydrate, and containing less than 300 mg cholesterol and 2,400 mg sodium per day. Analytic measures included analyses of variance, correlation analyses, and chi 2 tests. RESULTS Older subjects consumed more varied diets than did young subjects. Higher DVS values were linked positively to vitamin C intakes and negatively to the consumption of salt, sugar, and saturated fat. However, a high DVS was not linked to a high score on the DQI in this subject sample. DISCUSSION/CONCLUSIONS Few studies have addressed the issue of how many different foods constitute a varied diet. The present classification scheme offers a new way of assessing dietary variety at the individual or group level. Measures of dietary variety may represent an additional facet of diet quality and their relationship to selected health outcomes should be examined further.

Energy-dense diets are associated with lower diet costs: a community study of French adults

OBJECTIVE High consumption of energy-dense foods has been linked to high energy intakes and excess weight gain. This study tested the hypothesis that high energy density of the total diet is associated with lower diet costs. DESIGN Dietary intakes of 837 French adults, aged 18-76 years, were assessed using a dietary history method. Dietary energy density (MJ kg(-1)) was calculated by dividing total energy by the edible weight of foods consumed. Daily diet cost ( in day(-1)) was estimated using mean national food prices for 57 food items. The relationship between dietary energy density and diet cost at each level of energy intake was examined in a regression model, adjusted for gender and age. RESULTS The more energy-dense refined grains, sweets and fats provided energy at a lower cost than did lean meats, vegetables and fruit. Within each quintile of energy intake, diets of lower energy density (MJ kg(-1)) were associated with higher diet costs ( in day(-1)). CONCLUSION In this observational study, energy-dense diets cost less whereas energy-dilute diets cost more, adjusting for energy intakes. The finding that energy-dilute diets are associated with higher diet costs has implications for dietary guidelines and current strategies for dietary change.

Low-cost diets: more energy, fewer nutrients.

Energy-dense diets offer a low-cost dietary option to the consumer. However, they are more likely to be nutrient-poor. In this study, based on the French national food consumption survey, the diet costs were estimated using retail food prices in France. Adult participants were stratified by quartiles of energy cost (in [euro ;[sol;10 MJ). Dietary energy density, energy and nutrient intakes were then compared across groups. Participants in the lowest quartile of energy cost had the highest energy intakes, the most energy-dense diets and the lowest daily intakes of key vitamins and micronutrients. Participants in the highest quartile of energy cost had lower energy intakes, and diets that were higher in nutrients and lower in energy density. However, their daily diet costs were 165% higher. In this observational study, the more nutrient-dense diets were associated with higher diet costs.

The cost of US foods as related to their nutritive value

BACKGROUND Comparisons of the cost of different foods relative to their energy and nutritive value were conducted in the 1800s by the US Department of Agriculture (USDA). OBJECTIVE The objective was to reestablish the relations between food cost, energy, and nutrients by using contemporary nutrient composition and food prices data from the USDA. DESIGN The USDA Food and Nutrient Database for Dietary Studies 1.0 (FNDDS 1.0) and the Center for Nutrition Policy and Promotion food prices database were used for analysis. For 1387 foods, key variables were as follows: energy density (kcal/g), serving size (g), unit price (

Influence of Race, Ethnicity, and Culture on Childhood Obesity: Implications for Prevention and Treatment: A consensus statement of Shaping America's Health and the Obesity Society

/100 g), serving price (

Nutrient profiling of foods: creating a nutrient-rich food index

/serving), and energy cost (