You eat like a bird for the month leading up to a big event such as a class reunion
Slashing significant calories might sound like the fast track to weight loss, but it's likely to backfire. In fact, nutrition experts recommend you don't dip below 1,200 to 1,500 calories a day. "If you crash diet for more than 2 weeks or so, your metabolism will temporarily slow down," says Blackburn. "So the same exact dieting effort results in less and less weight loss." The reason: Your body is conserving energy to keep you from losing weight too quickly. And that's not all. When you drastically cut calories, you lose muscle along with fat — especially if you haven't been exercising. Because muscle is your body's calorie-burning furnace, this can slow down your metabolism, even long after your crash diet is done.Smarter move: Aim to shed about a pound a week — the slow, steady weight loss ensures you lose fat, not muscle. "If you want to drop 10 pounds, get started 10 weeks before your goal, not 4," says Blackburn. "You'll have a better chance of actually taking off the weight permanently." To drop a pound a week, shave 250 calories from your diet and burn an extra 250 calories through exercise each day.
You set short-term weight-loss goals
The National Weight Control Registry estimates that only 20% of dieters successfully keep off lost weight for more than a year. That's because after we reach our goal, we let old eating habits creep back in. But people who win at weight loss consistently eat the same way even after they've slimmed down. In fact, the NWCR found that dieters who maintain their healthy eating habits every single day are 1 1/2 times more likely to maintain their weight loss in the long run than those who relax their diets on the weekends.
Smarter move: Think of healthy eating as a work in progress, not as a "diet" with a beginning and an end. The key: making small changes you can maintain so they become long-term habits. Start by creating a list of problem areas in your diet, then tackle them one at a time. For example, if you snack on a heaping handful of Oreos every night before bed, set a goal of having two instead of six, and cut back by one a day. Once you've made that a habit, pat yourself on the back and move on to your next goal.
Your splurge foods are "low-fat" and "sugar-free"
Research suggests that when a food is described as a diet food, we're subconsciously primed to eat more — even if it's actually as caloric as regular food. When Cornell University researchers offered the same M&M's candies labeled either regular or low-fat to visitors at a university open house, visitors ate 28% more of the "low-fat" snacks. While less fat does not mean fewer calories, people make the assumption that it does, setting them up to overeat, say scientists.
Smarter move: First, check food labels: So-called diet foods frequently don't save you calories. Take low-fat chocolate chip cookies — because they've been infused with extra carbs to add flavor, you save only 3 calories per cookie. Once you have that reality check, follow the golden rule for any food: Keep close tabs on portions. Limit yourself to two small cookies, for example, or trade in a bowl of frozen yogurt for a kid's-size scoop; measure out condiments such as low-fat sour cream or low-fat ranch dressing. And remember — if you prefer the flavor of full-fat foods, you'll still lose weight if you watch your portion sizes.