Bad news if you, like me, have recently taken a vacation that involves overindulgence in high-calorie treats like (oh, just a few examples off the top of my head!) cheese, chocolate, crab cakes, pizza, and wine: Swedish researchers have discovered that overeating for even just a few weeks can have effects on body fat that last for years. In a study that's published in the journal Nutrition and Metabolism detailed here by the LA Times, one group of people was instructed to overeat and limit physical activity for four weeks, and then were followed for two years and compared to a control group. The chowhound group gained an average of 14 pounds, and a year later they were 3+ pounds heavier, on average, than the control group, and after two and a half years they were continuing to gain weight while the control group did not. The temporary overeaters also had higher levels of "bad" LDL cholesterol one year after the experiment ended.
So, if you're "waiting until after vacation" (or at other times of year it could be "after Christmas" or "after this stressful work period ends"—you get the idea) to reign in your eating, stop right now. Even if you're successful at switching back to your healthier habits, those weeks of overindulgence could very well be haunting your midsection and your metabolism for years to come. I've interviewed numerous highly respected diet experts over the years and one diet truth they always emphasize is that an "all or nothing" mentality is deadly to dieting and healthy weight maintenance. Tempting though it is, thinking "Hmm, since I had those doughnuts for breakfast I may as well write off the day and have a side of fries with lunch" always leads to irresponsible eating and weight gain, and this new research reveals that it can go beyond that to have lasting health effects. Another way to look at it is that every meal is a new chance to eat right.
An interesting side note: the LA Times says that most of the study subjects who were instructed to increase their caloric intake by a certain amount did so by eating two fast food meals a day. I wonder if that affected the results at all, and if you overeat for a month on home-cooked whole foods if it might be easier to return to a stable weight?