Protein is one of the most important nutrients for weight loss and toning. A high protein intake boosts metabolism, reduces appetite, and alters several weight-regulating hormones.
So protein can help you lose weight and belly fat through several different mechanisms.
In this article we explore all the links between protein and weight loss.
What is a protein?
Proteins are essential nutrients. They must be obtained through food for two reasons: nitrogen and essential amino acids (proteins are composed of 20 amino acids, 9 of which cannot be synthesized by the body).
Dietary protein must provide these elements to meet growth needs in children, and maintenance and energy needs in an adult human.
The quality of dietary proteins is measured by their source of nitrogen and essential amino acids.
Why does protein help burn calories?
After eating, some calories are used to digest and metabolize food. This is often called the thermic effect of food or thermogenesis .
Although not all sources agree on the exact figures, it is clear that protein has a much higher thermic effect than carbohydrates and fats.
A high protein intake tends to boost metabolism and increase the number of calories burned by about 80 to 100 per day. This effect is particularly pronounced when eating in a calorie surplus. In one study, overeating a high-protein diet increased calories burned by 260 per day.
By making you burn more calories, high-protein foods have a "metabolic advantage" over low-protein diets.
Does protein increase satiety?
Yes, protein meals can reduce hunger and appetite through several different mechanisms. This can automatically lead to a reduction in calorie intake.
Numerous studies have shown that when people increase their protein intake, they begin to eat fewer calories. In one study, protein at 30% of calories caused people to automatically reduce their calorie intake by 441 calories per day.
So, protein diets not only have a metabolic advantage, they also have a "satiety advantage," making it much easier to cut calories compared to low-protein diets.
We know that snacking is the worst enemy of weight loss diets. It's one of the main reasons why people tend to fail at their diets.
Many people who tend to gain weight have nighttime cravings, so they snack in the evening. These calories are added to all the calories consumed during the day. Interestingly, protein can have a powerful effect on cravings and the desire to snack at night.
One study compared a high-protein diet with a normal diet in overweight men. In this study, protein at 25% of calories reduced cravings by 60%, thus reducing the urge to snack late at night by half! Another study in teenage girls showed that a high-protein breakfast significantly reduced cravings.
How does protein affect weight loss?
Protein reduces calories in and increases calories out.
For this reason, it's not surprising to see that protein diets lead to weight loss, even without intentionally restricting calories, portions, fat, or carbohydrates.
In one study of 19 overweight people, increasing protein intake to 30% of calories led to a massive drop in calorie intake and therefore significant weight loss.
Higher protein intake is also associated with less abdominal fat, the fat that accumulates around organs and leads to long-term disease.
That being said, losing weight isn't the most important factor. It's maintaining your weight long-term that really matters. We're all familiar with the yo-yo diet phenomenon, where you diet, lose weight, and then keep putting it back on.
Interestingly, higher protein intake may also help prevent weight regain. In one study, a modest increase in protein intake (from 15 to 18% of calories) reduced weight regain after weight loss by 50%. So, not only can protein help you lose weight, but it can also help you maintain it long-term.
How do proteins play a role in weight-regulating hormones?
Your weight is actively regulated by the hypothalamus, an area of your brain. In order for your brain to determine when and how much to eat, it processes several different types of information.
One of the most important signals to the brain is the hormonal changes caused by diet. A higher protein intake increases satiety hormone levels while reducing your levels of ghrelin, the hunger hormone. By replacing carbohydrates and fats with protein, you reduce the hunger hormone and increase several satiety hormones.
This leads to a significant reduction in hunger, which is the main reason why protein helps you lose weight. You automatically reduce your calorie intake.
How much protein per day to lose weight?
You can count on about 1.2 to 1.8g per kilogram of body weight. When you want to lose weight, it's good to maintain a high protein ratio, as it has an appetite suppressant effect, promoting satiety, thus preventing you from overindulging.
Proteins to fight muscle loss.
Weight loss doesn't always mean fat loss. When you lose weight, muscle mass also tends to decrease. Muscle loss is often an unwanted consequence of weight loss.
Another side effect of weight loss is that your metabolic rate tends to decrease. In other words, you end up burning fewer calories than you did before you lost weight.
Eating plenty of protein helps with muscle mass gain, which should help maintain a higher metabolic rate as you lose body fat.
Exercise is another major factor that can reduce muscle loss and metabolic slowdown during weight loss. For this reason, high protein intake and intensive training are two extremely important components of an effective fat loss plan.
What are the best proteins for weight loss?
Plant-based proteins are an excellent choice for weight loss. Blends of sources such as rice, soy, or peas aren't just for vegans! This type of protein tends to promote satiety due to its slower absorption by the body.
Considering calories can help you make smart choices when choosing protein for weight loss. Opt for nutrient-dense protein sources low in saturated fat and calories, such as lean meats, seafood, beans, soy, low-fat dairy, nuts, and seeds.
Don't hesitate to mix and match several protein sources. For example, you could have salmon or other omega-3-rich fish, beans or lentils that provide fiber, and protein or nuts on your salad.
What are the highest protein foods?
Discover foods rich in protein in our dedicated article .
Otherwise, to boost your protein and vitamin intake, opt for OKR meal bars or powders and healthy snacks. This allows you to put your nutrition at the service of your body and your health. We select the best sources of plant-based protein for you in our recipes adapted to your daily energy needs. Ideal for quickly consuming between two meetings or after sports. For drinks, simply mix your dose of protein-rich meal powder in water and you're done!
