Over–nutrition and obesity are not the only causes of insulin resistance, which leads to abdominal fat and other health risks like diabetes, hypertension and coronary heart disease. Nutritional deficiencies and malnutrition can also be a reason for developing high blood pressure, diabetes, and heart disease. The role of magnesium deficiency in particular seems to be emerging as an important cause for insulin resistance, high blood pressure, diabetes, heart disease and metabolic syndrome, often even in the absence of obesity.

Magnesium is an essential mineral found abundantly in foods like whole grains, leafy green vegetables, legumes, peas, beans and nuts (especially almonds), and some shellfish. Magnesium plays an important role in several enzymatic reactions including carbohydrate metabolism in the body.

Many epidemiological studies have described inverse relationships between a magnesium–rich food intake and diabetes, insulin resistance and metabolic syndrome. In a Boston–based study in 2006, higher magnesium intake was associated with a 31 per cent lower risk of developing metabolic syndrome over 15 years of follow up. In another large study, called the Women's Health Study, high magnesium status was associated with a 27 per cent of lower risk of metabolic syndrome.

Profound changes in the environment occurred too fast for the genome to adjust. This led to the emergence of so–called diseases of civilisation, first described in agriculture, and that can be extended to the modern food industry. Intensive agriculture has been related to grass tetany in dairy cows, a disease due to an acute decrease of plasma magnesium. Similarly, food refining leads to a reduction of the micro–nutrient density and thereby induces a marginal magnesium intake, resulting in a higher prevalence of magnesium deficiency.

Recent findings confirm that the occidental (Western) diet is relatively deficient in magnesium. Moreover, a diet rich in animal foods and poor in vegetable foods induces acidosis and increases magnesium urinary excretion and causes magnesium depletion. There is experimental and clinical evidence that the amount of magnesium in urban and western diets is insufficient to meet individual needs and that magnesium deficiency may be contributing to common health problems. Data from the U.S. National Health and Nutrition Examination Survey showed that the average intake of magnesium was below the recommended daily intake. According to recent research published in March 2012 in Nutrition Reviews, more than half (56 per cent) of the US population consumed less than required amounts of magnesium from food in 2001–02, which corresponded to a sharp increase in type 2 diabetes in US.