Grains are small, hard, dry seeds, with or without attached hulls or fruit layers, harvested for human or animal consumption. The two main types of commercial grain crops are cereals (e.g. wheat, rye) and legumes (e.g. beans, soybeans). Seeds
After being harvested, dry grains are more durable than other staple foods, such as starchy fruits (e.g. plantains, breadfruit) and tubers (e.g. sweet potatoes, cassava). This durability has made grains well suited to industrial agriculture, since they can be mechanically harvested, transported, stored for long periods, and milled for flour or pressed for oil. Major global commodity markets exist for canola, maize, rice, soybeans, wheat, and other grains but not for tubers, vegetables, or other crops.
Overnutrition, a type of malnutrition, is emerging with rates of obesity and related chronic diseases associated with urbanisation, aging populations, technological development and globalisation of food supplies and industry. Billions of dollars are spent annually by the food industry to promote the consumption of highly refined, high-calorie foods with little or no nutritional value.
At least 35 million overweight children are living in developing countries and 8 million in developed countries. Children are increasingly exposed to high-fat, high-sugar, high-salt, energy-dense, micronutrient-poor foods which tend to be cheaper than healthy foods. General imbalance in energy intake compared to physical activity levels is driving the obesity epidemic. In industrialised countries, child obesity risk is associated with lower household income, women with less education, and single parent households.
Obesity is increasingly prevalent among adolescent girls and women, as access to a greater quantity of inexpensive, tasty, and convenient foods increases.
Taxation on high-calorie, low-nutrition foods can play a significant role in reducing the consumption of such products. Population-wide weight-control campaigns that raise awareness among medical staff, policy-makers and the public at large can also help to reduce obesity. Particularly important is the promotion of health literacy. Additional measures include restrictions on the marketing of unhealthy foods and sugary drinks to children, and controls on the use of misleading health and nutrition claims; mandatory front-of-pack food labelling helps consumers to identify healthier options.