The saying, "a moment on the lips, a lifetime on the hips" may be truer than ever, according to a new study that finds eating foods high in fat and sugar actually trigger the body to store excess fat.

The study published in the FASEB Journal has found that foods high in fat and sugar stimulate a known opioid receptor – called the kappa opioid receptor – which plays a role in fat metabolism. When this receptor is stimulated, it causes our bodies to hold on to far more fat than our bodies would do otherwise.

Scientists involved with the study tested the effects of a Western-style diet high in fat, sucrose and energy-dense on two sets of mice – one that had their kappa opioid receptor genetically deactivated and one control group – for a period of 16 weeks. They found that the regular group gained weight while the group that had their kappa opioid receptors knocked-out remained lean.

Researchers say more research is needed to determine the effects of the study on humans. However, they say their findings support avoiding a diet high in fat and sugar, and may help develop new therapies for weight loss.

Some health practitioners have suggested the alkaline diet for those trying to shed extra pounds. It is based on citrus fruits, vegetables, tubers, nuts and legumes.