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  • Ari Winfield

Protein and weight loss

Following on from my post last week about guidelines for the consumption of protein (and its respective amino acids), I wanted to delve a little bit deeper into how you can use protein to help you reach your goals, weight loss in particular. Let’s go!

High thermogenic effects

OK, starting off with the thermic effect of food… did you know that you actually expend energy (burn calories) by eating?

Well, not just through the ingestion of food, there’s also the energy used in the digestion, absorption, and utilisation and storage. The thermic effect of food accounts for 6 - 10% of daily energy expenditure for men, and around 6 - 7% for women.¹

Different foods require different amounts of energy to process, however.

Protein has high thermogenic effects, it’s estimated that 25 - 30% of the calories in protein are burned as it’s digested!²

The corresponding figures are much lower for carbs - around 6 - 8%, and fat around - 2 - 3%.³

This means that if you were to consume 100 calories of protein, the process of digestion would burn 25 - 30 calories and your body would only have 70 - 75 calories available after digestion. But if you were to consume 100 calories of fat, your body would have 97 - 98 calories still left to use.⁴

Protein is ‘satiating’…

The Cambridge dictionary defines ‘satiating’ as ‘to completely satisfy yourself or a need, especially with food or pleasure, so that you could not have any more’.⁵

When it comes to food, if I haven’t got that full and satiated feeling after a meal, I’m not happy, and you’ll soon find me on the scrounge to find more food to fulfil that need.

Studies show⁶ that protein is by far the most filling macronutrient (over carbohydrates and fat). It helps you feel more full — with less food. As a result, eating a protein-rich diet can help people lose weight because it can help them avoid overeating.

In addition, they also take longer to leave your stomach, so you feel full sooner and for a longer amount of time.

In one study⁷, increasing protein intake from 15% to 30% of calories made overweight women eat 441 fewer calories each day without intentionally restricting anything.⁷

High protein diets can build lean muscle…

When combined with exercise - hypertrophy in particular - a high protein diet will support you in building muscle. And do you know what muscle does? It increases your metabolism and helps to burn more calories throughout the day. The NHS explains in a little more detail how muscle mass affects the metabolisms of different groups:

“Muscle cells require more energy to maintain than fat cells, so people with more muscle than fat tend to have a faster metabolism.
As we get older, we tend to gain fat and lose muscle. This explains why your metabolism may slow down as you get older.
In general, men tend to have a faster metabolism because they have more muscle mass, heavier bones and less body fat than women”.⁸

The verdict?

Whilst obviously a calorie deficit is the most important part of a weight loss program, evidence shows that the cumulative effects that come as a result of increasing your protein intake can really support you along the way.

Hope this helps,




  1. Poehlman, 1989.

  2. NASM, 2017.

  3. Gunnars, 2013.

  4. NASM, 2017.





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