Most of us can grit our teeth, go on a diet, and lose some fat. Most popular diets, ranging from keto to veganism, really do succeed at helping people lose weight (study, study). The problem is that motivation ebbs and flows.
When you finish a successful diet, you’re still the same person you were before. You still have the same appetite—the same stomach. The difference is you’re carrying less weight and burning fewer calories. That can make it extremely difficult to stay lean.
A pound of muscle burns around 6 calories per day at rest, but you also need to carry it around with you, causing it to burn closer to 12 calories per day. If you can gain 20 pounds of muscle, that’s an extra 240 calories burned without needing to do any extra exercise. If you build enough muscle while losing fat, you can eat the same amount of food you were eating before without regaining fat. That helps, but it’s still not the most important part.
The main reason lifting weights is so powerful is that when you inevitably start to regain weight, you’ll build muscle instead of storing fat. Your metabolism will increase as you build that muscle. You’ll eventually settle at a weight that’s easier to maintain.
How to Burn Fat More Easily
Maintaining a lean physique can be difficult. Our modern lifestyles have less physical activity paired with greater food availability, and much of that food is delicious and calorically rich. There’s quite a bit of individual variation in metabolism, too, making it even more difficult for some than others.
There are a few ways you can make burning fat easier:
- Burn a ton of calories. The more calories you burn, the more you can eat without getting fat.
- Find a way to eat a satisfying amount of food. If your appetite cues you to eat the correct number of calories, you won’t accidentally gain weight.
- Invest your extra calories in muscle instead of storing them as fat. If you can stimulate enough muscle growth, then when you eat in a small calorie surplus, those calories will be invested into muscle growth instead of being stored as fat.
How Lifting Weights Can Help
Lifting weights stimulates muscle growth, causing the extra calories you eat to thicken your biceps instead of your belly. You can speed this process along by eating enough protein, but even just lifting weights causes muscle growth (and often fat loss).
If you’re new to lifting weights, you can expect to gain around 0.5 pounds of muscle per week during your first few months of lifting. You should be able to build around 10–20 pounds of muscle in your first year. That can save you from gaining 10–20 pounds of fat.
How Muscle Burns Calories
The extra muscle you build will speed up your metabolism. A pound of fat burns around 2 calories per day at rest. A pound of muscle burns 6. That’s where most people get confused. It makes it seem like 10 pounds of muscle burns the same amount as 30 pounds of fat. That isn’t quite right.
We need to carry our weight around with us. When we factor that in, a pound of fat burns closer to 8 calories per day, and a pound of muscle burns closer to 12. If you want to keep your metabolism high, you need to build quite a lot of muscle.
Fortunately, training to build muscle burns more calories. You can also build a bit more physical activity into your lifestyle. Going on a short but brisk walk every morning and lifting weights 3x per week can work wonders on your health, fitness, and body composition.
How Protein Burns Calories
Eating more protein burns more calories. When you digest food, some of the energy is burned off as body heat. This phenomenon is called the Thermic Effect of Food (TEF). If you’ve ever eaten a big meal and then felt hot afterwards, that’s why.
Each macronutrient has a different TEF, meaning that some types of calories are more easily burned off as body heat, whereas others are more easily stored as body fat (source):
- If we eat 1000 calories of fat, our bodies burn 15 calories as heat.
- If we eat 1000 calories of carbs, our bodies burn 75 calories as heat.
- If we eat 1000 calories of protein, our bodies burn 250 calories as heat.
That means that if you cut 44 grams of fat (400 calories) out of your diet and replace it with 100 grams of protein (400 calories), you’ll be burning 98 more calories per day. In theory, that would be enough to lose ten pounds of fat per year (or to ward off ten pounds of fat gain).
How Being Heavier Reduces the Hunger
Being heavier reduces our appetite. Our bodies have built-in mechanisms that discourage us from losing too much weight. There was a time when this was a favourable adaptation, but it doesn’t suit our modern way of living. Food is too plentiful.
Your body can sense when there’s less weight weighing down on your bones. If you get too much lighter, your appetite hormones will kick in, filling you with a ravenous hunger.
When your willpower is high, you can resist those cravings. But your willpower can’t stay high forever, and eventually, you will succumb to that hunger. And besides, even during the best of times, who wants to have their willpower constantly sapped by food cravings?
If you build muscle, you can stay substantially heavier. Maybe not as heavy as we were before, but not light either. And if we factor in that a pound of muscle burns four more calories per day than a pound of fat, managing your appetite starts to become more realistic.
If we add up all these factors, lifting weights could either help you lose an extra thirty pounds of fat per year or—just as important—stop you from regaining the fat that you lose.