6. Fast once a week: While regularly underfeeding your body completely messes with your hormone balance, there’s sufficient research to suggest that intermittent fasting (IF)—or going without any food for set intervals—can actually help your insulin sensitivity and burn more fat. Researchers at LSU, for example, found that when people fasted all day, every other day, their fat oxidation increased and they actually lost 4 percent of their body fat in just 22 days. There are a lot of ways to go about IF, from fasting for 12 to 16 hours every day, to going 24 hours once a week. (Learn more about it here.)
It’s that kind of accessibility that makes running one of the best workouts for weight loss. “You just need a pair of decent shoes, some creativity, and maybe a friend or two to develop a walking or running plan,” says Daniel O’Connor, Ph. D., professor of health and human performance at the University of Houston. “It’s less expensive than joining a gym or having a personal trainer.”
5. Hydroxycitric Acid (HCA): The name sounds scary, but this supplement is derived from a salt in a Southeast Asian fruit plant. And the perks are real: HCA can help decrease the amount of visceral, subcutaneous, and total fat on your body, according to a study in the Journal of Obesity. It works by suppressing your appetite, reducing the amount of fat your body absorbs from your diet, and increasing your metabolism.
Over the past five or six days of this protocol, you’ve been in deep ketosis and burning only fat, but you haven’t had to be particularly calorie restricted. In order to reset leptin levels and prevent a large drop in energy levels, you need to re-feed. Contrary to our normal recommendations, you need to pound down the carbs. When it comes to normalizing leptin levels, fat has no effect, while carbs are going to send them sky high.
In what is perhaps the biggest buzzkill of all time, sex doesn’t quite count as cardio or burn a significant amount of calories: Women burn about 3.6 per minute. "It’s still a good idea," Dr. Seltzer says, citing the activity’s other benefits, like increasing the output of the neurotransmitters serotonin and dopamine, which naturally reduce food cravings.
This may explain why the fat-burning effects of eating more protein were confirmed in a study published in the American Journal of Physiology. One group was fed a high-protein diet (just over 1 gram per pound of body weight per day) while the second group consumed an amount closer to the lower recommendation of the RDA (recommended dietary allowance). The group eating the higher-protein diet burned the most fat.