Have you ever seen an overweight bug? Insects are able to avoid overweight over generations by evolving metabolically to adjust to changes in their diets.

Entomologists with the Texas Agricultural Experiment Station along with other researchers recently conducted a series of studies to see how caterpillars would adapt over several generations to changes in their diet. They found that when the insects were fed diets rich in carbohydrates and low in protein, their bodies were able to eat the high carbohydrate diet without gaining excess weight. But when the diet was changed to one low in carbohydrates and high in protein, the caterpillars’ bodies adjusted by storing the carbohydrates as fat, enabling them to maintain weight.

Scientists suggest that the human nutritional environment has changed dramatically over the past century, from a diet higher in protein and low in carbohydrates to one high in carbohydrates, especially refined sugar - but we, unlike the caterpillars, are unable to change our metabolic processes and so we convert the excess carbohydrate to fat.