This article has been Fact-Checked by Kendall Kennedy MS, RD, RYT
You might have heard that protein can help a lot for weight loss. Why is that and how much do you need?
What exactly is protein?
Protein is an essential macronutrient which means that it contains calories and everyone needs to consume it in sufficient quantities in one way or another. Carbohydrates and fats are the other macronutrients.
The reason for this is that protein is an important building block of body tissue.
Protein itself is made of smaller building blocks called amino acids. When you consume food with protein your body breaks it down into amino acids that can be used to make your own proteins.
How much protein should you eat when trying to lose weight?
The amount of protein you need for weight loss depends on a few different factors. Even then the science isn’t entirely clear on what the “best” amount is. There are however estimations.
In general it’s better to have a little “too much” protein than too little, certainly when you’re trying to lose weight.
Some factors that influence how much you need are body weight, body composition, age and what your exercise routine looks like.
If you don’t exercise and are under 65 years old you should aim for a daily intake of around 0.36 grams of protein per pound of body weight (+-0.8 grams / kg of body weight). Preferably consuming 2/3’s of that amount in a single meal.
If you exercise a lot you can aim a little higher. When you are trying to build a lot of muscle you can even go up to a daily intake of 0.50 grams of protein per pound (1.1 grams /kg) and higher.
If you are 65+ years old you can add 10-20% to these daily amounts. This is because older people tend to lose more muscle mass and bone density. The increased amount of protein can help slow this process down.
The numbers are pretty much the same for men and women alike.
These quantities are estimates for optimal longevity. Do consult your primary care provider before making any drastic changes in your diet.
When should you eat more?
There are reasons you can eat more protein than the amounts above.
Protein heavy foods are usually effective against hunger and cravings. The downsides of eating a little more protein usually outweigh the downsides of eating processed foods like cookies or candy.
If eating more protein is the thing that helps you stay away from junk food it’s most likely a good trade-off.
Keep in mind that the mentioned quantities are “grams of protein” not “grams of protein containing food”.
If you’re not sure what foods can help you reach your daily goals this list of 28 high protein foods for weight loss is for you.
How does protein help you lose weight?
Protein is arguably the best macronutrient for weight loss. There are a few benefits that make it extremely helpful.
Satiating
Protein is more satiating compared to carbohydrates and fats (1, 2, 3).
This can make you eat less of other foods by helping you feel less hungry.
Muscle growing and preserving
Your body uses protein to grow and repair muscles. By consuming enough you can stimulate growth and preserve it better.
Muscle is extremely helpful for losing weight. It helps you burn more calories 24/7. That’s why weight lifting is such an effective weight loss exercise.
More energy to process a calorie of protein
Your body uses energy (calories) to break down the foods you eat into usable nutrients.
Processing protein takes your body more calories than processing carbohydrates and fats. This won’t come down to 100’s of calories a day but small bits do add up.
What happens if you don’t eat enough protein?
In most developed countries protein deficiency isn’t very common. However, dieting can get people to do some interesting things to themselves.
Too little protein can cause some very negative things to your body.
Examples of this are swollen body parts, fatty liver, skin hair and nail problems, increased risk of bone fracture and even death if you go to the extremes.
Protein deficiency also leads to loss of muscle mass. Especially in the case of losing weight that is really not what you want.
It’s clear that you want to eat enough protein.
What if you have too much protein?
Protein is still a macronutrient which means it contains calories. If you have too much it might be harder to achieve a calorie deficit. However, it’s certainly possible to lose weight if you eat too much protein.
Having too much can also put a little extra strain on your kidneys. For most people this won’t be such a big problem but for people with weak kidneys this might be something to avoid.
Only getting your protein from whole food sources can help you avoid eating too much.
What is the best kind of protein?
It’s usually smart to eat a wide variety of foods. This is because different foods contain different micronutrients.
If you consume protein only by eating plant based foods, chances are you will be deficient in vitamins like B12 if you don’t supplement it.
In general it’s agreed upon that fish is one of the best sources of protein.
Plant based proteins usually also provide you with some extra fiber. Fiber is also great if you’re looking to lose weight.
Nutrition is basically of puzzle of getting enough of all the different important nutrients. Some food sources contain other kinds of nutrients than others so variety is almost always smart.
Different foods also contain different amino acids in different quantities with different effects. At the moment there is no perfect amino acid ratio known.
Should you use a protein supplement?
Most people are easily able to get enough protein from the foods they eat.
It’s most likely smarter for you to get your protein from whole foods that contain other helpful nutrients instead of protein supplements that can have substances negative for your health.
