There’s a misconception that you need plenty of protein when your goal is building muscle, but less when you’re going through a cutting phase or otherwise trying to lose fat. In fact, you may stall or completely derail your fat loss efforts if you’re not getting enough protein.
There are a few important reasons why you need to make sure you’re getting enough protein while you’re trying to lose fat.
Adequate Protein Allows You To Build Calorie-Burning Muscle
The most efficient way to create a calorie deficit is to pack on more lean muscle. 70% of your base metabolic rate (the amount of calories you need for basic function) is based on your lean body mass. The more muscle you have, the more calories you burn.
Even if you’re trying to lose body fat, you should still be doing at least some resistance training to add lean muscle mass to your frame and either increase your allowed intake or speed up your fat loss.
Even if you’re a bodybuilder going through a cutting period, you still need to do some resistance to maintain the muscle you already have.
Without adequate protein, you’re not going to have the protein you need to enable muscle recovery and repair. Your body partitions protein metabolism. In other words, it takes the protein it needs for healthy brain and organ function and allows the rest to be used as fuel or for muscle repair. If you’re not getting enough dietary protein, all of your work in the gym will be going to waste and you’ll likely see some muscle loss as well.
If You Don’t Eat Enough, Your Body Will Get Its Protein Elsewhere
Your body will get the protein it needs, one way or another.
If you’re on a calorie-restricted diet and cutting protein to make that deficit higher, your body will simply start breaking down the protein stored in muscle tissue. This is why so many people lose weight on a low-calorie diet, only to end up looking worse than they did before.
If your fat loss goal is intended to reveal lean muscle and a shapely body, you need to retain (or add to) your muscle mass while you’re losing the fat.
Also, getting adequate protein while on a calorie deficit prevents your body from sending out warning signals to your hormones that actually stop fat loss. Without enough protein on board, your sensitivity to the satiety hormone leptin will decrease, making it much harder to feel satisfied throughout the day and leading to overeating.
Don’t Cut the Protein, Just Get it from Leaner Sources
Most people immediately think of meats when they look at increasing protein in their daily diets, but meats aren’t the only source of protein out there.
If you’re already getting enough dietary fat (including some saturated fats) and just need to increase your protein intake, you have lots of choices.
Whey protein is low fat, low sugar and low in calories. It’s also extremely bioavailable, far more so than the protein in most meats. Add a protein shake to your daily meal plan or simply add a scoop of whey protein to your fruit smoothie or hot cereal.
Fish and shellfish are much lower in fat than most meats, so add one or two seafood meals per week. Fatty, cold water fish are best for those Omega-3 fats and shrimp, mussels, crab, clams, oysters and lobster are all great low-fat, low-calorie protein sources as long as you donlt drench them in butter. Try olive oil with freshly-ground pepper, hot sauce, cocktail sauce or a mustard vinaigrette instead.
Sweet potatoes, legumes, quinoa, peas, lentils and dark, leafy greens are all low in fat and low in calories, plus they’ll add lots of filling fiber to your meal.
How Much Protein Do You Really Need?
If you’re trying to add lean muscle while you lose fat, most researchers recommend 1-1.5g of protein per kilogram of body weight. If you simply want to lose fat and maintain the muscle you already have, .7-1g should do nicely.
If you find that muscle building slows or you feel hungry during the day, try upping your protein intake by 10% each day until you find your sweet spot.
Whatever you do, don’t assume that you can speed up your fat loss by trimming your calories too low and cheating your body of nutrients. This will result in short term weight loss, but much of that weight will be lean muscle and most or all of it will return even more quickly than you lost it.
For permanent and healthy weight loss, you need to work with your body rather than trying to trick it into letting go of fat.
Bill Campbell et al. International Society of Sports Nutrition position stand: protein and exercise. Journal of the International Society of Sports Nutrition. 2007, 4:8.
Douglas Paddon-Jones, Eric Westman, Richard D Mattes, Robert R Wolfe, Arne Astrup, and Margaret Westerterp-Plantenga. Protein, weight management, and satiety. American Journal of Clinical Nutrition. May 2008 vol. 87 no. 5
Joy L Frestedt, et al. A whey-protein supplement increases fat loss and spares lean muscle in obese subjects: a randomized human clinical study. Nutrition and Metabolism (London). 2008; 5: 8.