If you do, you are starving yourself, slowing your metabolism, and preventing muscle growth. While it is great to employ a little bit of cardio to help augment your deficit, you should never do so much cardio that your deficit puts you below your BMR. SO DON’T DO IT! This includes Cardio, too!Ĭreating too large of a caloric deficit through cardio exercise is the same thing as starving your body by not eating. This is especially important if you are fighting to lose that last 10lbs of fat. If you do-regardless of how much fat you have to lose-you encourage adaptive thermogenesis. If your BMR is 1500 calories, you should never eat less than 1500 calories in a day. You never want your total caloric intake to be less than your BMR. For this reason… No matter your goal, you must ALWAYS eat at or above your BMR. As you start to eat at normal levels again, your body directs calories toward fat storage for the next time you starve it… and then the pounds come back. You stop eating, you lose a few pounds-much of it water-but your body thinks something is wrong and slows your metabolism in an effort to protect you from starving to death. Duh. That’s the problem with crash diets: the yo-yo phenomenon. The last thing you want to do when you are trying to lose weight is to slow down your metabolism. When you stop eating, your body says to itself, “Oh, shit! I better save my energy in case he doesn’t find more food! Wait, why is it taking him so long to find food? What is the f’ckin’ problem?” The less you eat, the harder it is to lose weight over time. 1 Īs a way to protect itself from death, your body “slows down” by avoiding bodily functions that are superfluous, and your metabolism slows down so that you can store whatever small amount of food you are getting. When you stop eating altogether, your body goes into “starvation mode,” a.k.a “adaptive thermogenesis.”Īdaptive thermogenesis was then defined as the decrease in energy expenditure beyond what could be predicted from body weight or its components (fat-free mass and fat mass) under conditions of standardized physical activity in response to a decrease in energy intake. Your body is DESIGNED to survive for as long as it can without food. Maybe you’re thinking, “I usually eat about 3000 calories a day, so I’ll fast for 6 days and then I’ll be down at least five pounds. How you spread that deficit out over the course of weeks determines how quickly you will lose fat, as well as how able you are to hold onto (or gain) muscle. If there are 3500 calories in a pound of fat, and your goal is to burn that pound of fat off your body (either through exercise or just by being alive) you need to accumulate a deficit of 3500 calories. Use these numbers–they work–and adjust as needed as you progress.Īs discussed, you need to maintain a caloric deficit to lose weight. (The more weight you lose, the harder it is to lose weight… we’ll describe why that happens in a second.) But, you need to start your calculations somewhere, and this is a great place to start, especially if you have a lot of fat to lose. There is research to dispute that number, because fat loss is not a linear process. (I will cover my macro-nutrient breakdowns in a future post.) There are roughly between 34 calories in 1 lb of fat mass.Ĭonventional wisdom tells us that 3500 calories is a solid estimate. Your body needs a mix of carbohydrate, protein, and fat to perform at it’s best. While different foods have different nutritional content, and your body converts different materials into energy in different ways… a calorie is always a calorie. For the sake of time, I’m going to present this in US customary units, but you can figure it out from that.)Ī calorie is a calorie is a calorie. (That’s 770kcal in kilogram of fat, for my friends using the metric system. There are 3500 calories in a pound of fat.

These calculations have worked for me over the past few years, and they WILL work for you. I’m going to break-down my recommendations for using your BMR to determine how many calories you should eat to maintain a healthy, productive deficit. Or maybe you want to lose fat while also gaining muscle, which can be done, especially if you are new to strength training.

Maybe you want to lose fat without losing muscle. Maybe, you have a lot of fat to lose and that is your only goal, for now. For more detailed info about BMR, calculating a caloric deficit, and much more, check out the book! In order to determine an ideal caloric deficit, you need to determine your goals. The following is an early draft of a chapter in my book, How I Did It: A Fitness Nerd’s Guide to Losing Fat and Gaining Lean Muscle.

Bmr calculator for weight loss