Protein is the single most important nutrient for weight loss and a better looking body. A high protein intake boosts metabolism, reduces appetite and changes several weight-regulating hormones.
Protein can help you lose weight and belly fat, and it works via several different mechanisms.
This is a detailed review of the effects of protein on weight loss.
Protein Changes The Function of Several Weight Regulating Hormones
A higher protein intake actually increases levels of the satiety (appetite-reducing) hormones GLP-1, peptide YY and cholecystokinin, while reducing your levels of the hunger hormone ghrelin. By replacing carbs with fat and protein, you reduce the hunger hormone and boost several satiety hormones.
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.
Digesting and Metabolizing Protein Burns Calories
Digesting and metabolizing protein takes 3-4 times the calories as for carbs, and 10 times the calories required to metabolise fats.
Protein Makes You Burn More Calories
Due to the high thermic effect and several other factors, a high protein intake tends to boost metabolism. It makes you burn more calories around the clock, including during sleep.
A high protein intake has been shown to boost metabolism and increase calories burned by about 80 to 100 per day.
Protein Increases Satiety and Makes You Eat Fewer Calories
You end up eating fewer calories without having to count calories or consciously control portions.Numerous studies have shown that when people increase their protein intake, they start eating fewer calories.
This works on a meal-to-meal basis, as well as a sustained day-to-day reduction in calorie intake as long as protein intake is kept high.
In one study, protein at 30% of calories caused people to automatically drop their calorie intake by 441 calories per day, which is a huge amount .
So, high protein diets not only have a metabolic advantage – they also have an “appetite advantage,” making it much easier to cut calories compared to lower protein diets.
Protein Cuts Cravings and Reduces Desire for Late-Night Snacking
Cravings are the dieter’s worst enemy. They are one of the biggest reasons why people tend to fail on their diets.
Another major problem is late-night snacking. Many people who have a tendency to gain weight get cravings at night, so they snack in the evening. These calories are added on top of all the calories they ate during the day.
Interestingly, protein can have a powerful effect on both cravings and the desire to snack at night.
This graph is from a study comparing a high-protein diet and a normal-protein diet in overweight men:
The high-protein group is the blue bar, while the normal-protein group is the red bar.
In this study, protein at 25% of calories reduced cravings by 60% and cut the desire for late-night snacking by half!
Protein Makes You Lose Weight, Even Without Calorie Restriction
Protein works on both sides of the “calories in vs calories out” equation. It reduces calories in and boosts calories out. For this reason, it is not surprising to see that high-protein diets lead to weight loss, even without intentionally restricting calories, portions, fat or carbs.
In one study of 19 overweight individuals, increasing protein intake to 30% of calories caused a massive drop in calorie intake:
In this study, the participants lost an average of 11 pounds over a time period of 12 weeks. Keep in mind that they only added protein to their diet, they did not intentionally restrict anything.
A higher protein intake is also associated with less belly fat, the harmful fat that builds up around the organs and causes disease.
Interestingly, a higher protein intake can 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, it can also help you keep it off in the long-term.
Protein Helps Prevent Muscle Loss and Metabolic Slowdown
You probably don’t really want to lose “weight.” Instead, you want to lose body fat, both subcutaneous (under the skin) fat and visceral (around organs) fat.
However, when you lose weight, muscle mass tends to be reduced as well.
Another side effect of losing weight is that the metabolic rate tends to decrease, so you end up burning fewer calories than you did before you lost the weight. This is often referred to as “starvation mode,” and can amount to several hundred fewer calories burned each day.
Eating plenty of protein can reduce muscle loss, which should help keep your metabolic rate higher as you lose body fat.
Strength training is another major factor that can reduce muscle loss and metabolic slowdown when losing weight.
For this reason, a high protein intake and heavy strength training are two incredibly important components of an effective fat loss plan.
Not only do they help keep your metabolism high, they also make sure that what is underneath the fat actually looks good. Without protein and strength training, you may end up looking “skinny-fat” instead of fit and lean.
How Much Protein is Optimal?
The DRI (Dietary Reference Intake) for protein is only 46 and 56 grams for the average woman and man, respectively. This amount may be enough to prevent deficiency, but it is far from optimal if you are trying to lose weight (or gain muscle). Or even just stay healthy!
Most of the studies on protein and weight loss expressed protein intake as a percentage of calories. According to these studies, aiming for protein at 30% of calories seems to be very effective for weight loss.
You can find the number of grams by multiplying your calorie intake by 0.075. For example, on a 2000 calorie diet you would eat 2000 * 0.75 = 150 grams of protein.
You can also aim for a certain number based on your weight. For example, aiming for 0.7-1 gram of protein per pound of lean mass is a common recommendation (1.5 – 2.2 grams per kilogram). It is best to spread your protein intake throughout the day by eating protein with every meal.
Keep in mind that these numbers don’t need to be exact, anything in the range of 25-35% of calories should be effective.
Even though eating more protein is simple when you think about it, actually integrating this into your life and nutrition plan can be difficult.
I recommend that you use a calorie/nutrition tracker in the beginning. Weigh and measuring everything you eat in order to make sure that you are hitting your protein targets. You don’t need to do this forever, but it is very important in the beginning until you get a good idea of what a high-protein diet looks like.
Protein is The Easiest, Simplest and Most Delicious Way to Lose Weight
When it comes to fat loss and a better looking body, protein is the king of nutrients.
You don’t need to restrict anything to benefit from a higher protein intake. It is all about adding to your diet.
This is particularly appealing because most high-protein foods also taste really good. Eating more of them is easy and satisfying.
A high-protein diet can also be an effective obesity prevention strategy, not something that you just use temporarily to lose fat.
By permanently increasing your protein intake, you tip the “calories in vs calories out” balance in your favor.
Over months, years or decades, the difference in your waistline could be huge.
However, keep in mind that calories still count. Protein can reduce hunger and boost metabolism, but you won’t lose weight if you don’t eat fewer calories than you burn.
It is definitely possible to overeat and negate the calorie deficit caused by the higher protein intake, especially if you eat a lot of junk food.
For this reason, you should still base your diet mostly on whole, single ingredient foods.
Although this article focused only on weight loss, protein also has numerous other benefits for health. See http://drlilykiswani.com/10-science-backed-reasons-to-eat-more-protein/.
And Stay Healthy!