Why to spread protein across your meals while dieting and how much to aim for each day

When people start eating less, meat, fish, eggs and tofu are often the first things to disappear from the table. People on weight-loss medication may also eat less protein as their appetite drops. The book I co-wrote, Eat to Succeed (a Korean-language book, 2026), covers how to spread protein through the day across several chapters.

Muscle is built and broken down over and over throughout the day. Chapter 4 of the book explains that muscle building is especially active for 3-4 hours after eating protein, and that in the remaining hours without protein, muscle is actually broken down. If you eat only two meals a day, you get only two of those chances.

When muscle goes too, your basal metabolic rate falls and you regain weight more easily on the same amount of food. That is why Chapter 8 says protein is essential for staying full and keeping muscle.

Even so, if you expect weight to fall much faster just by eating more protein, you may be disappointed. One analysis pooled 24 randomised trials with 1,063 people comparing diets with the same calories but more protein against standard diets. Over an average of 12 weeks, the higher-protein diets led to 0.79 kg more weight loss and 0.87 kg more fat loss, and 0.43 kg less loss of fat-free mass (the weight that is not fat). The direction is clear, but the difference is under 1 kg.

We are often asked how much to eat a day. In clinic we ask whether you are getting at least 1 g of protein per kg of body weight a day and whether you do strength training at least twice a week. If you weigh 60 kg, that is at least 60 g a day.

A number on its own is hard to picture, so we put it in terms of food. Chapter 8 notes that one egg has 6 g of protein. Greek yoghurt has about twice the protein of ordinary yoghurt, and tofu is low in calories and easy to digest. Mackerel and salmon give you protein and omega-3 together.

Many people also ask whether they should leave out the yolk. The book says two or three eggs a day do not have a large effect on cholesterol levels, so you can eat the nutritious yolk too.

Many people think that a generous portion of meat at dinner covers the day's protein. The book gives different amounts depending on how many times you eat. On the 3.6.9 plan, eating five times a day at three-hour intervals, you add 10-15 g to every meal and snack. If you eat three meals, aim for 20-30 g at each meal.

One study checked whether eating more at once builds more muscle. It gave 17 young adults and 17 older adults lean beef containing either 30 g or 90 g of protein and measured muscle protein synthesis for five hours. Synthesis rose by about 50% after 30 g, and three times as much (90 g) did not raise it any further. It was a small study measuring a single meal, so it cannot simply be stretched to a whole day.

At lunch and dinner, fill half the plate with vegetables and split the rest evenly between protein and whole grains. On days you exercise, have low-fat protein such as yoghurt or chicken breast within 30 minutes of finishing.

If you already eat three regular meals and do not eat large amounts in one go, there is no need to add snacks just to get more protein. Put protein in each of your three meals.

Many people stock up on protein bars and shakes first when they decide to eat more protein. Chapter 8 puts both on its list of hidden calories. Protein bars look healthy, but many are high in sugar and calories and can reach 200-300 kcal each. When choosing one, check the label for no more than 200 kcal, at least 10 g of protein and no more than 10 g of sugar per bar, or make your own.

Shakes can easily go over 800 kcal once you add banana, peanut butter and honey. Mix protein powder with water or unsweetened almond milk and a few berries, and keep it under 400 kcal.

Digesting protein also takes a lot of energy. Chapter 4 says 20-30% of the calories in protein are used to digest it, compared with 5-10% for carbohydrates and 0-3% for fat. That does not mean you can eat as much protein as you like without gaining weight. The other 70-80% of the calories still count.

Some people come in after losing weight because their cheeks have sunk and they are looking into treatment. If InBody shows a clear drop in skeletal muscle mass, the problem is not only in the face. In that case we put treatment on hold and rework the diet first. If muscle has gone too, working on the face alone tends to end up back where it started a few months later.

People on weight-loss medication sometimes eat less protein as their appetite drops. Chapter 7 of the book also says to have 20-30 g of protein such as eggs, chicken breast, fish or tofu at every meal. Once weight has held steady for about two months, we start talking about treatment, and in the meantime we check protein intake and muscle mass first.