And that raises the most important point: Thinking about exercise as a way to work off food or simply allow you to eat sets up a host of unhealthy and unhelpful thought patterns and habits around food and exercise. For instance, one 2013 research review found that, not only did people generally overestimate how many calories exercise burned—when they did work out, they ramped up their food intake. And if you overeat following exercise, any caloric deficit created during your workout can become a wash. And related: thinking of food as a reward and exercise as a punishment is likely to sabotage your weight loss efforts anyway.
Why does HIIT training work better than conventional cardio for fat loss? When you do cardio at the same pace, your body adjusts itself to the workload and tries to conserve calories. (After all, your body doesn't know how long or hard you plan to work out.) Interval training forces your body to burn more calories -- and tap into fat stores -- because it has no choice. Science says so: One study at Laval University found people who performed HIIT cardio lost nine times more fat than people who performed moderate cardio at a consistent speed.
Two weeks doesn’t give you much time to trigger noticeable changes in your body. To negate the time factor, you’ll be condensing the work schedule. Over the next 14 days, you’ll put in 12 total workouts, with two rest days built in. The increased frequency of workouts will up the number of calories you’re burning over the course of the program. By keeping repair and recovery constant between workouts, you’ll have your metabolism working overtime to keep up. This type of schedule is not sustainable in the long term, but you’ll find that your body can do almost anything for a two-week block, often with positive results.
Try not to eat when you feel upset or bored — find something else to do instead (a walk around the block or a trip to the gym are good alternatives). Many people find it's helpful to keep a diary of what they eat and when and what they are feeling. When you have to write it down, you might think twice before eating cookies. Reviewing the diary later can also help them identify the emotions they have when they overeat.
You should already be following a diet to get lean, and should therefore be aware of how much you’re eating. But to remove any guesswork, we’ll give you some numbers to hit for the week: Consume one gram of protein and 10–11 calories for every pound of your body weight; 20% of those daily calories should be from fat, and the remainder from carbs. (Remember to first subtract the protein calories you’re also eating from the total allowed before you calculate the number of carbs.)
Ah, the über-popular “know your why” strategy. One Brown University study found that when people are motivated to lose weight for appearance and social reasons, they stick with their weight-loss habits for significantly less time than those who are motivated by their health. After all, these external motivators (like looking a certain way or fitting into a cultural ideal) aren’t going to get you going when you’re feeling down, have had a bad day, or are frustrated with a plateau, Albers says.
If you eat a carbohydrate-rich meal (lots of pasta, rice, bread, or French fries, for example), your body releases insulin to help with the influx of all this glucose into your blood. As well as regulating blood sugar levels, insulin does two things: It prevents your fat cells from releasing fat for the body to burn as fuel (because its priority is to burn off the glucose) and it creates more fat cells for storing everything that your body can’t burn off. The result is that you gain weight and your body now requires more fuel to burn, so you eat more. Since insulin only burns carbohydrates, you crave carbs and so begins a vicious cycle of consuming carbs and gaining weight. To lose weight, the reasoning goes, you need to break this cycle by reducing carbs.
We often make the wrong trade-offs. Many of us make the mistake of swapping fat for the empty calories of sugar and refined carbohydrates. Instead of eating whole-fat yoghurt, for example, we eat low- or no-fat versions that are packed with sugar to make up for the loss of taste. Or we swap our fatty breakfast bacon for a muffin or donut that causes rapid spikes in blood sugar.
Also some research shows that the human body is primed to consume most of its calories during daylight hours. But the lifestyle is problematic for many: Because family meals and dinners with friends often are scheduled for after sunset, "people who try to stop eating after 7pm can’t do it every day for the rest of their lives," says Dr. Seltzer, who supports an alternative strategy: Eating a hearty meal at your regular dinnertime.