Researchers from Deakin University in Australia sought to compare the effects of short-term and long-term bouts of overeating. They took a small group of lean, healthy men with an average age of 22 and put them on high-calorie diets for a period of five days—to represent indulging over the holidays, and then 28 days—to represent a period of more chronic overeating.
According to the study's authors, a typical Australian diet consists of 55% carbohydrates, 35% fat, and 15% protein. The researchers sought to maintain similar macronutrient percentages while adding an additional 1,000 calories to their diets. The young men added calorie-dense (but maybe less nutritious) foods like potato chips, chocolate bars and meal replacement shakes to boost their intake.
The participants' weight, fat mass, blood sugar, and insulin levels were measured before and after both the five and 28-day trials. Researchers found after the five-day trial that while visceral fat increased substantially, short-term periods of overeating didn't have a significant impact on weight or fat mass. They also found blood sugar fasting levels didn't change, noting the body has the ability to adapt to short bouts of indulging.
Data from the 28-day trial found that the participants' total and visceral fat increased, along with post-meal blood sugar levels. Fasting blood sugar levels were not altered, which the authors attribute to the nutrient profile of the indulgent diets remaining relatively consistent with that of a typical diet. The authors of the study said long-term overindulgence in fatty foods instead of more nutritionally balanced foods could be an important factor in controlling blood sugar.
The bottom line: While your pants may feel a bit more snug after the holidays or a series of vacation buffets, that's OK! Occasionally feasting can be part of a balanced diet, and unless you're making it a regular habit, you probably don't need to worry about the long-term consequences (though you may want to try these recovery foods if you've just overeaten). Listening to your body's hunger and fullness cues while surround by indulgent foods is the best way to stay on track while enjoying the foods you love and making cherished memories with loved ones.