Protein is one type of macronutrient. The other two are fats and carbohydrates.

People will debate about the benefits of cutting out carbs and fats until the end of time, but the importance of protein for weight loss (or fat loss) is widely recognized.

Here are 3 reasons why protein is so important for weight loss:

#1: Protein makes you eat less automatically

A higher protein intake increases levels of the satiety (appetite-reducing) hormones GLP-1, peptide YY, and cholecystokinin, while reducing your levels of the hunger hormone ghrelin.

This leads to a major reduction in hunger and is the main reason protein helps you lose weight. It can make you eat fewer calories automatically.

Numerous studies have shown that when people increase their protein intake, they start eating fewer calories.

In one study, when people increased their protein intake to 30% of their daily calories they automatically dropped their total calorie intake by 441 calories per day, which is a huge amount. For most people, that’s the deficit required to lose weight safely and sustainably.

Protein also has a powerful effect on both cravings and the desire to snack at night.

The graph below is from a study comparing a high-protein diet and a normal-protein diet in overweight men.

The high-protein group is the green bar, while the normal-protein group is the blue bar.

In this study, protein at 25% of calories reduced cravings by 60% and cut the desire for late-night snacking by half.

#2: Digesting and metabolizing protein burns calories

After you eat, some calories are used for the purpose of digesting and metabolizing the food.

This is called the thermic effect of food (TEF).

Although not all sources agree on the exact figures, it is clear that protein has a much higher thermic effect (20-30%) compared to carbs (5-10%) and fat (0-3%).

This means for every 100 calories of protein consumed, only 70-80 ‘count’.

Due to the high thermic effect and several other factors, a high protein intake also tends to boost metabolism.

It makes you burn more calories around the clock, including during sleep.

#3: Protein helps prevent muscle loss and metabolic slowdown

Weight loss doesn’t always equal fat loss.

When you lose weight, muscle mass is often lost as well.

This is a problem because a loss in muscle mass is associated with a decline in metabolic rate.

In other words, you end up burning fewer calories than you did before you lost the weight.

This is what is sometimes referred to as ‘starvation mode’ and explains, in part, why weight loss can become more difficult the closer you get to your goal.

Additionally, maintenance of muscle mass is essential for a strong, able body and a firm or ‘toned’ appearance.

Eating plenty of protein helps prevent muscle loss when you lose weight.

It can also help keep your metabolic rate high, especially when combined with resistance training.

Protein helps you lose weight long-term, even without conscious calorie restriction

Protein works on both sides of the “calories in vs calories out” equation. It reduces calories in and boosts calories out.

Even without intentionally restricting calories, portions, fat or carbs, high-protein diets lead to significant weight loss.

Unlike other ‘diets’, which typically only work in the short-term, a higher protein intake can also help prevent weight regain. In one study, a modest increase in protein intake reduced weight regain after weight loss by 50%.

Bottom line:

If your goal is to lose weight and keep it off, then consuming an adequate amount of protein from quality sources should be your top priority.


1. Photo by Geraud Pfeiffer from Pexels