Prevailing thinking about obesity and related diseases holds that quantifying calories should be a principal concern and target for intervention. Part of this thinking is that consumed calories – regardless of their sources – are equivalent; i.e. ‘a calorie is a calorie’. The present commentary discusses various problems with the idea that ‘a calorie is a calorie’ and with a primarily quantitative focus on food calories. Instead, the authors argue for a greater qualitative focus on the sources of calories consumed (i.e. a greater focus on types of foods) and on the metabolic changes that result from consuming foods of different types. In particular, the authors consider how calorie-focused thinking is inherently biased against high-fat foods, many of which may be protective against obesity and related diseases, and supportive of starchy and sugary replacements, which are likely detrimental. Shifting the focus to qualitative food distinctions, a central argument of the paper is that obesity and related diseases are problems due largely to food-induced physiology (e.g. neurohormonal pathways) not addressable through arithmetic dieting (i.e. calorie counting). The paper considers potential harms of public health initiatives framed around calorie balance sheets – targeting ‘calories in’ and/or ‘calories out’ – that reinforce messages of overeating and inactivity as underlying causes, rather than intermediate effects, of obesity. Finally, the paper concludes that public health should work primarily to support the consumption of whole foods that help protect against obesity-promoting energy imbalance and metabolic dysfunction and not continue to promote calorie-directed messages that may create and blame victims and possibly exacerbate epidemics of obesity and related diseases.

Increasingly more studies are raising concerns about the increasing consumption of meat and the increasing amount of crops (cereals and oilseeds in particular) used to feed animals and that could be used to feed people. The evolution of this amount is very sensitive to human diets and to the productivity of feed. This article provides a 2050 foresight on the necessary increase in crop production for food and feed in three contrasting scenarios: diets with no animal products; current diets in each main region of the world; and the average diet of developed countries extended to the whole world. We develop empirical aggregate production models for seven world regions, using 43 years and 150 countries. These models realistically account for the contribution of feed from food plants (i.e. plants that would be edible for humans) and of grassland to animal products. We find that the amount of edible crops necessary to feed livestock in 2050 is between 8% and 117% of today's need. The latter figure is lower than that in comparable foresight studies because our models take into account empirical features occurring at an aggregate level, such as the increasing share of animal production from regions using less crop product per unit of animal product. In particular, the expected increase in animal production is estimated to occur mostly in Sub-Saharan Africa and Asia, where the amount of feed from food crops required per unit of animal product proves to be lower than that in other areas. This 117% increase indicates that crop production would have to double if the whole world adopted the present diet of developed countries.

Background: Mounting evidence implicates diets high in fats and processed sugars with increased generation of free radicals in animals. It is still not clearly established whether such a diet alters antioxidant balance in dementia patients, where an oxidative stress status may already exist. The disruption to lipid metabolism by oxidative stress has been recently linked to neurodegeneration and clinical disease. The aim of this study is to assess the relationship between fat, sugar, carbohydrate and caloric intake levels, and antioxidant status in patients with mild to moderate dementia.

Methods: The levels of 3 essential endogenous antioxidants (superoxide dismutase, catalase, glutathione peroxidase) were measured in the blood of 26 dementia subjects and 26 cognitively unimpaired controls. Concurrently, the intake levels of relevant nutrients and dietary antioxidants were assessed in all subjects.

Results: A statistically significant positive association was observed in the dementia group between glutathione peroxidase activity and the intake of fats (r=0.44; p=0.023), carbohydrates (r=0.46; p=0.018), total sugars (r=0.51; p=0.007) and calories (r=0.47; p=0.14). The only significant association in the control group was observed between glutathione peroxidase and fat (r=0.47; p=0.015).

Conclusion: The higher glutathione peroxidase activity among subjects with greater intake of fats, carbohydrates and sugars may represent a compensatory response to the additional increase in oxidative stress in dementia. Our data shed light on the influence of dietary intake on the oxidant-antioxidant system in mild to moderate dementia patients.