The conventional advice for losing body fat is to “eat less and move more.”
Unfortunately, this near-sighted approach ignores how our physiology reacts when we exercise. The body has a finely tuned system that allows it to sense how many calories are coming in and how many are going out.
A region of the brain responds by altering release of hormones that impact hunger and make you feel lazier and less energetic. This is one reason that long cardio sessions tend to be ineffective for fat loss. They stimulate appetite and people end up eating more after exercise.
Known as “compensation,” scientists also think there may be a psychological factor at play, whereby people reward themselves for exercise-related activities with treats and other foods that make them overshoot their daily calories.
This doesn’t mean that exercise should be avoided. Rather, there appears to be a “sweet spot” for most people when they are getting just enough physical activity, but not so much that hunger hormones and appetite get out of whack.
If you find you have a voracious appetite after working out, or are in the habit of compensating with treats, you might want to adjust your workouts.
Additionally, although more research is needed, some studies indicate that strength training and other forms of anaerobic exercise tend to minimize the boost in hunger that is associated with increased exercise, so this might be the ideal alternative if you are getting into trouble with long-duration cardio.
For example, you could train with weights for about an hour 3 or 4 days a week and on your remaining workout days, do high-intensity intervals. Studies show that interval training (such as repeated 30-second maximal effort sprints interspersed with 3 to 4 minutes recovery) can blunt appetite, while revving your metabolism.
Another factor to consider is the carbohydrate/exercise continuum. The body uses glycogen and glucose, two forms of carbohydrates, to fuel exercise.
Exercise naturally sensitizes the muscle cells to insulin—the hormone that allows the body to burn glucose. Insulin is a storage hormone and when levels are elevated, the body is more likely to store energy as fat. When cells are naturally more sensitive to insulin, less of this hormone is needed to store the same amount of glucose, which means that the body will spend more time in fat burning mode.
This is good news for everyone who loves carbs because it means your carbohydrate requirements increase on heavy workout days. Additionally, after exercise is the best time to load up on carb-rich foods because your cells are both ravenous for carbs and ready to bind with insulin.
That said, it’s still important to choose complex “healthier” carbs instead of refined “junk food” carbs: Say “yes” to sweet potatoes but “no” to potato chips. “Yes” to blueberries but “no” to skittles. Swap a piece of fruit for a granola bar. Substitute spaghetti squash for pasta. Choose steel cut oats instead of boxed cereal.
Exercise is a great tool for weight management and it plays a pivotal role in fat loss. However, you need to take some precautions to maximize the benefits:
Monitor your appetite on workout days. Be aware that hunger may not increase until hours after training (or even the next day). If you find yourself ravenous, consider adjusting your workouts away from long duration cardio in favor of anaerobic versions like intervals and weight training.
You can minimize overeating by establishing a fixed eating schedule and avoid snacking in between meals. It’s also recommended to avoid skipping meals since this often backfires when people make indulgent calorie-heavy choices once appetite is elevated.
Watch out for compensation: If you aren’t losing weight despite your best efforts, consider whether you are in the habit of rewarding yourself. Many people don’t even recognize they are doing it until they do a food journal that shows them they have been on a dietary free-for-all after tough workouts.
In addition to pre-planning post-workout meals, be smart about pre-workout meals. Before exercise, it’s generally recommended that you eat a high-protein meal that contains complex carbs and healthy fat to elevate amino acids in the blood for protein synthesis, and minimize hunger. If you prefer to train fasted, be sure not to overeat post-workout.
The best time of day to eat carbs is after a tough workout because muscles will be starving for glucose. Insulin sensitivity is enhanced and carbs may promote recovery by lowering cortisol in the post-workout period. Unless you are doing high volumes of training, such as two-a-day workouts, opt for complex carbs, such as sweet potatoes and other root vegetables, fruit, and whole grains.