If you've made the decision to lose weight, you might be wondering where to begin.
To help you get started, Live Science spoke with many weight loss experts and combed the literature on the topic. Here are some tips for getting started on a weight loss program:
Take a close look at your current lifestyle
Before you embark on a weight loss program, it's a good idea to think carefully about your current lifestyle and to identify behaviors that might have contributed to weight gain. One way to do this is to keep a food diary, in which you log all the food you eat for a few days. This helps you become more aware of what you eat, and when, according to the Centers for Disease Control and Prevention.
Then, you can think in more concrete ways about how you might change some of your habits to work toward losing weight. For example, keeping a log might help you realize that when you skip meals, you tend to overeat later on. Or, you might find that you eat an extra 500 calories at the office on days when co-workers bring in treats.
With a concrete plan in place, you can establish new behaviors, like eating four smaller meals a day so you aren't so hungry later on, or eating healthier foods that will help keep your appetite satisfied for longer, said Liz Applegate, director of sports nutrition at the University of California, Davis.
Set a realistic goal
Determine how much weight you want to lose, and set short-term goals along the way to your ultimate goal. Doctors generally recommend that people aim to lose 5 to 10 percent of their body weight over six months. But to get there, you should make specific, short-term goals, such as taking three 20-minute walks per week, or always having vegetables with dinner, according to the CDC.
It's also important that your goals be realistic. With lifestyle changes, you should expect gradual, steady weight loss, but not immediate results.
"There's no diet that's going to be healthy long term that will help you lose 20 pounds over a month," said Dr. Pieter Cohen, an assistant professor of medicine at Harvard Medical School.
Calculate your caloric intake
To lose weight, you'll need to consume fewer calories than you burn. The exact number will depend on your current weight and activity level, but generally, people should aim to cut 250 to 1,000 calories from their diet per day in order to lose 0.5 to 2 lbs. (0.23 to 0.9 kilograms) per week. You can use a calculator, such as the National Institutes of Health Body Weight Planner, to determine how many calories a day you need to consume to maintain your current weight and how many you need to cut out to lose weight.
Monitor your progress
Finally, you should keep track of your progress toward your goals and tweak them if needed. "Studies are clear that self-monitoring is important," said Katherine Tallmadge, a registered dietitian and op-ed contributor to Live Science. For example, you may want to use a pedometer or other device to keep track of how far you're walking, Tallmadge said.
If you seem to be having trouble meeting a goal, see how you can refine the goal or your behaviors in order to meet it. For example, if you haven't been able to fit in a morning walk as you resolved to do, see if you can fit the walk in at lunchtime instead, the CDC says. On the other hand, if a goal you set is too easy, see if you can make it more challenging.
This article is part of a Live Science Special Report on the Science of Weight Loss.
Follow Rachael Rettner @RachaelRettner. Follow Live Science @livescience, Facebook & Google+. Original article on Live Science.