Tempted to overindulge? Remind yourself why you want to stay healthy.

WHAT IT MEANS: When tempted to skip your trip to the gym or reach for “just one cookie,” remind yourself of the benefits of sticking to a healthy program. Better yet, set some long-term goals for yourself that you can call to mind when you feel like giving up. “The more we keep the focus on general goals and how we’re going to go about achieving them, we’ll be healthier in the long run,” Agrawal says.

Setting goals is easy; sticking to them is the hard part. Here are a few suggestions for staying on track.

• It’s okay to be vague. You can focus on losing a certain number of pounds, but as Agrawal says, general goals aimed at improvements in overall well-being and health are just as effective. Other research backs her up: A study at the University of Michigan found that 40- to 60-year-old women who exercised with a goal of improving their overall well-being were 34 percent more likely to stick with their plan than women focused only on losing weight.

• Keep it simple. Agrawal’s study and others like it show that you can’t make too many demands on your brain’s capacity for self-control in a given day. If you set too many goals for yourself, you weaken your willpower and are more likely to cheat.

• Get between 7 and 8 hours of sleep. The participants in this experiment quickly lost their ability to care about health messages after they’d been put through the ringer by difficult tasks. Other research has shown that getting less than 6 hours of sleep can hamper people’s ability to make smart decisions.