Coinciding with this increase in weight are ever-rising rates of heart disease, diabetes, cancer and health complications caused by obesity, such as hypertension. Even Alzheimer’s disease may be partly attributable to obesity and physical inactivity.
“The diet in the U.S. and other nations has changed dramatically in the last 50 years or so, with highly processed foods readily and cheaply available at any time of the day or night,” Ali Güler, a professor of biology at the University of Virginia, said. “Many of these foods are high in sugars, carbohydrates and calories, which makes for an unhealthy diet when consumed regularly over many years.”
In a study published Thursday in the journal Current Biology, Güler and his colleagues demonstrate that the pleasure center of the brain that produces the chemical dopamine, and the brain’s separate biological clock that regulates daily physiological rhythms, are linked, and that high-calorie foods — which bring pleasure — disrupt normal feeding schedules, resulting in overconsumption. Using mice as study models, the researchers mimicked the 24/7 availability of a high-fat diet, and showed that anytime snacking eventually results in obesity and related health problems.