Biomedical subjects

Nicole Darmon

Publications and source records attributed to Nicole Darmon.

12 recordsLinked to original sources

PubMed2006

Design of optimal food-based complementary feeding recommendations and identification of key "problem nutrients" using goal programming.

The WHO is urging countries to promote improved complementary feeding practices to ensure optimal health, growth, and development of young children. To help achieve this, a rigorous 4-phase approach for designing optimal population- specific food-based complementary feeding recommendations (CFRs) was developed and is illustrated here. In phase I, an optimized diet is selected, using goal programming (Model #1), which aims to provide a desired nutrient content with respect to habitual diet patterns and cost. Based on its food patterns, a set of draft CFRs is designed. In phase II, their success for ensuring a nutritionally adequate diet is assessed via linear programming (Model type #2) by sequentially minimizing and maximizing the level of each nutrient (i.e., worst and best-case scenarios) while respecting the CFRs. For nutrients that are <70% of desired levels, the best food sources are identified via linear programming in phase III (Model #3). Different combinations of these foods are incorporated into the original draft of the CFRs to produce alternative CFRs, which are then compared on the basis of their cost, flexibility, and "worst-case scenario" nutrient levels (Model type #2) to select, in phase IV, a final set of CFRs. A hypothetical example is used to illustrate this approach. Outcomes include a set of optimal, population-specific CFRs and practical information regarding key "problem nutrients" in the local diet. Such information is valuable for nutrition promotion, as well as nutrition program planning and advocacy, to help achieve global initiatives for improving the complementary feeding practices of young children living in disadvantaged environments.

Breast Feeding↗

PubMed2005

A nutrient density standard for vegetables and fruits: nutrients per calorie and nutrients per unit cost.

OBJECTIVES: The Dietary Guidelines for Americans 2005 recommended that consumers give priority to nutrient-dense foods, those that contain substantial amounts of key nutrients in relation to the dietary energy they provide. This study developed a scoring system to estimate the nutritional adequacy of vegetables and fruits, on a per weight, per calorie, and per unit cost basis. DATA: We used a French national food composition database for 637 foods, including 129 vegetables and fruits. Mean national retail prices were obtained for each food. METHODS: The nutrient adequacy score was defined as the mean of percent daily values for 16 nutrients, based on 100 g of food. The nutrient density score and the nutrient-to-price ratio were the mean of percent daily values for 16 nutrients, expressed per 100 kcal and per 1 euro of food, respectively. Relationships between energy density of vegetables and fruits, nutrient adequacy score, nutrient density score, and nutrient-to-price ratio were tested using linear regression. RESULTS: Energy density and nutrient density score were negatively correlated, confirming the widely accepted notion that energy-dense foods tend to be nutrient-poor. As expected, fruits and vegetables had the highest nutrient density score because they were nutrient-rich in relation to their low energy content. They also had a relatively high nutrient-to-price ratio, showing that they provided nutrients at a reasonable cost when compared with other foods. CONCLUSIONS: Foods ranked differently when nutritional adequacy was calculated per weight (nutrient adequacy score), per calorie (nutrient density score), or per unit cost (nutrient-to-price ratio). The present results showed that although fruits and vegetables are an expensive source of dietary energy, they provide key nutrients at a reasonable cost.

Biological Availability↗

PubMed2005

The economics of obesity: dietary energy density and energy cost.

Highest rates of obesity and diabetes in the United States are found among the lower-income groups. The observed links between obesity and socioeconomic position may be related to dietary energy density and energy cost. Refined grains, added sugars, and added fats are among the lowest-cost sources of dietary energy. They are inexpensive, good tasting, and convenient. In contrast, the more nutrient-dense lean meats, fish, fresh vegetables, and fruit generally cost more. An inverse relationship between energy density of foods (kilojoules per gram) and their energy cost (dollars per megajoule) means that the more energy-dense diets are associated with lower daily food consumption costs and may be an effective way to save money. However, economic decisions affecting food choice may have physiologic consequences. Laboratory studies suggest that energy-dense foods and energy-dense diets have a lower satiating power and may result in passive overeating and therefore weight gain. Epidemiologic analyses suggest that the low-cost energy-dense diets also tend to be nutrient poor. If the rise in obesity rates is related to the growing price disparity between healthy and unhealthy foods, then the current strategies for obesity prevention may need to be revised. Encouraging low-income families to consume healthier but more costly foods to prevent future disease can be construed as an elitist approach to public health. Limiting access to inexpensive foods through taxes on frowned upon fats and sweets is a regressive measure. The broader problem may lie with growing disparities in incomes and wealth, declining value of the minimum wage, food imports, tariffs, and trade. Evidence is emerging that obesity in America is a largely economic issue.

Costs and Cost Analysis↗

PubMed2005

Food choices and diet costs: an economic analysis.

Obesity in the United States is a socioeconomic issue. It is related to limited social and economic resources and may be linked to disparities in access to healthy foods. Added sugars and added fats are far more affordable than are the recommended "healthful" diets based on lean meats, whole grains, and fresh vegetables and fruit. There is an inverse relationship between energy density of foods (kJ/g) and energy cost ($/MJ), such that energy-dense grains, fats, and sweets represent the lowest-cost dietary options to the consumer. Good taste, high convenience, and the low cost of energy-dense foods, in conjunction with large portions and low satiating power, may be the principal reasons for overeating and weight gain. Financial disparities in access to healthier diets may help explain why the highest rates of obesity and diabetes are found among minorities and the working poor. If so, then encouraging low-income households to consume more costly foods is not an effective strategy for public health. What is needed is a comprehensive policy approach that takes behavioral nutrition and the economics of food choice into account.

Choice Behavior↗

PubMed2004

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.

Adolescent↗

PubMed2004

Food-based dietary guidelines can be developed and tested using linear programming analysis.

Effective food-based dietary guidelines (FBDGs) are required to combat micronutrient deficiencies. This study aimed to develop a rigorous approach for designing population-specific FBDGs. A 4-phase approach based on linear programming analysis was used to design, test, and refine the FBDGs. This was illustrated for Malawian children. In phase I, the objective function minimized the difference in the energy contributed by different food groups between modeled and observed diets for 16 observed diet types, while preferentially selecting foods most often consumed. Constraints ensured nutrient adequacy and diet palatability. In phase II, the meal/snack patterns of the phase I modeled diets were examined to develop season-specific FBDGs. In phase III, the robustness of these FBDGs, for ensuring a nutritionally adequate diet, was tested. The objective function, in this analysis, minimized selected nutrient levels in the modeled diets (i.e., chose the "worst-case scenario"), while respecting the FBDGs, palatability, and energy constraints. The FBDGs were refined in phase IV. In the Malawian example used to illustrate our approach, the FBDGs promoted daily consumption of maize flour, small dry fish (>or=20 g), leaf relish, and 2-3 snacks. The last mentioned included mangoes, in the food-shortage season, and pumpkin in the food-plenty season. In addition, legume relish was recommended in the food-shortage season. The approach presented here can be used to design and then test the robustness of FBDGs for meeting nutrient recommendations.

Animals↗

PubMed2004

Replacing fats and sweets with vegetables and fruits--a question of cost.

OBJECTIVES: We examined the association between diet quality and estimated diet costs. METHODS: Freely chosen diets of 837 French adults were assessed by a dietary history method. Mean national food prices for 57 foods were used to estimate diet costs. RESULTS: Diets high in fat, sugar, and grains were associated with lower diet costs after adjustment for energy intakes, gender, and age. For most levels of energy intake, each additional 100 g of fats and sweets was associated with a 0.05-0.40 per day reduction in diet costs. In contrast, each additional 100 g of fruit and vegetables was associated with a 0.18-0.29 per day increase in diet costs. CONCLUSIONS: Diets high in fats and sweets represent a low-cost option to the consumer, whereas the recommended "prudent" diets cost more.

Adult↗

PubMed2003

Do economic constraints encourage the selection of energy dense diets?

Economic constraints, by inducing the selection of low cost energy dense diets, could indirectly be responsible for the high prevalence of obesity in low socio-economic status groups. Diet optimisation by linear programming was used to test this hypothesis, by examining the relationship between the cost and the energy density (ED) of modelled diets. Models were developed that minimized the departure from the mean adult French diet estimated from a cross-sectional dietary survey. Palatability constraints were introduced into all models. The impacts of cost on ED and of ED on cost were explored by introducing and strengthening first a constraint on cost and then a constraint on ED. Forcing the cost of the linear programming diets to decrease induced a strong increase in their EDs. In contrast, forcing the ED to increase induced only a moderate decrease in diet costs. These results suggest that, although an energy dense diet can be selected at a relatively high cost, when cost is not influencing food choices, an energy dense diet will be preferentially selected to maintain habitual French dietary patterns when the budget for food is low. This supports the hypothesis that economic constraints play a role in the high prevalence of obesity in low-income people.

Adult↗

PubMed2003

Linear programming: a mathematical tool for analyzing and optimizing children's diets during the complementary feeding period.

During the complementary feeding period, children require a nutrient-dense diet to meet their high nutritional requirements. International interest exists in the promotion of affordable, nutritionally adequate complementary feeding diets based on locally available foods. In this context, two questions are often asked: 1) is it possible to design a diet suitable for the complementary feeding period using locally available food? and 2) if this is possible, what is the lowest-cost, nutritionally adequate diet available? These questions are usually answered using a "trial and error" approach. However, a more efficient and rigorous technique, based on linear programming, is also available. It has become more readily accessible with the advent of powerful personal computers. The purpose of this review, therefore, is to inform pediatricians and public health professionals about this tool. In this review, the basic principles of linear programming are briefly examined and some practical applications for formulating sound food-based nutritional recommendations in different contexts are explained. This review should facilitate the adoption of this technique by international health professionals.

Diet↗

PubMed2002

Linear and nonlinear programming to optimize the nutrient density of a population's diet: an example based on diets of preschool children in rural Malawi.

BACKGROUND: Food consumption surveys are often used to detect inadequate nutrient intakes but not to determine whether inadequate nutrient intakes are due to suboptimal use of locally available foods or to insufficient availability of nutrient-dense foods. OBJECTIVES: The objectives were to describe the use of linear programming as a method to design nutrient-adequate diets of optimal nutrient density and to identify the most stringent constraints in nutritional recommendations and food consumption patterns in a population's diet. DESIGN: This analysis was conducted with the use of food consumption data collected during 2 seasons from rural Malawian children aged 3-6 y. Linear programming was used to select diets based on local foods that satisfied a set of nutritional constraints while minimizing the total energy content of the diet. Additional constraints on daily intakes of foods and food groups were also introduced to ensure that the diets were compatible with local food patterns. The strength of the constraints was assessed by analyzing nonlinear programming sensitivity. RESULTS: In the harvest season, it was possible to satisfy nutritional recommendations with little departure from the local diet. In the nonharvest season, nutritional adequacy was impaired by the low availability of riboflavin- and zinc-rich animal or vegetable foods and by the high phytate content of other foods. CONCLUSIONS: This analysis suggests that nutrition education may help improve the diets of children in the harvest season, whereas changes in the range of available foods might be needed in the nonharvest season. Linear and nonlinear programming can be used to formulate recommendations with the use of data from local food consumption surveys.

Child↗

PubMed2002

A cost constraint alone has adverse effects on food selection and nutrient density: an analysis of human diets by linear programming.

Economic constraints may contribute to the unhealthy food choices observed among low socioeconomic groups in industrialized countries. The objective of the present study was to predict the food choices a rational individual would make to reduce his or her food budget, while retaining a diet as close as possible to the average population diet. Isoenergetic diets were modeled by linear programming. To ensure these diets were consistent with habitual food consumption patterns, departure from the average French diet was minimized and constraints that limited portion size and the amount of energy from food groups were introduced into the models. A cost constraint was introduced and progressively strengthened to assess the effect of cost on the selection of foods by the program. Strengthening the cost constraint reduced the proportion of energy contributed by fruits and vegetables, meat and dairy products and increased the proportion from cereals, sweets and added fats, a pattern similar to that observed among low socioeconomic groups. This decreased the nutritional quality of modeled diets, notably the lowest cost linear programming diets had lower vitamin C and beta-carotene densities than the mean French adult diet (i.e., <25% and 10% of the mean density, respectively). These results indicate that a simple cost constraint can decrease the nutrient densities of diets and influence food selection in ways that reproduce the food intake patterns observed among low socioeconomic groups. They suggest that economic measures will be needed to effectively improve the nutritional quality of diets consumed by these populations.

Costs and Cost Analysis↗

PubMedDate not supplied

Impact of a cost constraint on nutritionally adequate food choices for French women: an analysis by linear programming.

OBJECTIVE: To predict, for French women, the impact of a cost constraint on the food choices required to provide a nutritionally adequate diet. DESIGN: Isocaloric daily diets fulfilling both palatability and nutritional constraints were modeled in linear programming, using different cost constraint levels. For each modeled diet, total departure from an observed French population's average food group pattern ("mean observed diet") was minimized. RESULTS: To achieve the nutritional recommendations without a cost constraint, the modeled diet provided more energy from fish, fresh fruits and green vegetables and less energy from animal fats and cheese than the "mean observed diet." Introducing and strengthening a cost constraint decreased the energy provided by meat, fresh vegetables, fresh fruits, vegetable fat, and yogurts and increased the energy from processed meat, eggs, offal, and milk. For the lowest cost diet (ie, 3.18 euros/d), marked changes from the "mean observed diet" were required, including a marked reduction in the amount of energy from fresh fruits (-85%) and green vegetables (-70%), and an increase in the amount of energy from nuts, dried fruits, roots, legumes, and fruit juices. IMPLICATIONS: Nutrition education for low-income French women must emphasize these affordable food choices.

Adolescent↗