The income-elasticity of calories, macro- and micro-nutrients: What is the literature telling us?

• Significant heterogeneity in reported estimates of calories and nutrients income-elasticity
• Calories and proteins are rather income-inelastic whereas fat and micronutrients are sensitive to income changes.
• Substantial publication bias for sizes of income-elasticity of calories and nutrients
• Journals' prestige, quality of data, and data frequency bias estimates on income-elasticity of calories and nutrients

Food security and nutrition have become central to the policy agendas of governmental and non-governmental organizations due to their consequences on health and economic development. Changes in consumption patterns in response to price and income changes could impact on nutrient intake with related positive or negative consequences. This article aims to systematically review the elasticity of calories, macronutrients and micronutrients to income in developing and developed countries. We consider a large set of estimates on income elasticity for calories, protein, fat, zinc, iron and vitamin A. This is one of the few reviews that examines the estimates for income elasticity of calories, micronutrients, and micronutrients on a comparative basis. Moreover, we investigate the determinants of the heterogeneity in estimates by means of a rigorous and popular approach of meta-analysis. We found a substantial publication bias, and, in particular, we found that the quality of data is very important as it is able to influence estimates.