By Dr. Asnat Raziel, bariatric surgeon specializing in obesity treatment, metabolic health and healthy longevity; Director of the Multidisciplinary Center for Obesity Treatment, Assia Medical, Assuta Ramat HaChayal, Tel Aviv
Protein intake: why everyone is talking about it
In recent years, protein intake has become the hottest topic in nutrition. Supermarket shelves are packed with “high-protein” products. Social media is flooded with tips on shakes and powders. So many people ask whether they really need to eat a lot of protein, and if so, how much.
The answer goes much deeper than marketing slogans. Protein is one of the body’s essential macronutrients. It affects almost every system: muscles, the immune system, hormones, bones, the brain and even how full we feel.
Why do we need protein at all?
Protein is made of amino acids, the body’s building blocks. It’s essential for building and maintaining muscle mass. In addition, the body uses it to make enzymes, hormones and antibodies. Protein also helps wounds heal and supports recovery from illness and surgery. It supports bone health and helps keep you feeling full. In fact, every cell in the body needs protein to function.
Protein intake and weight loss
One of the most important findings of the past decade concerns the role of protein during weight loss. When you lose weight, you lose fat, but also some muscle mass. Losing muscle can slow your metabolism and weaken strength and function. What’s more, it makes it harder to keep the weight off over time.
A meta-analysis of 24 studies compared high-protein, low-calorie diets with standard diets. On the high-protein diet, participants lost an average of 0.87 kg more fat. At the same time, they kept 0.43 kg more lean mass. That’s why every modern obesity treatment program today emphasizes getting enough protein. You can read more in my article on preserving muscle mass during weight loss.
Protein and feeling full
Of the three macronutrients (carbohydrates, fats and proteins), protein is the most filling. A review in the American Journal of Clinical Nutrition found that a high-protein meal increases fullness and raises levels of satiety hormones. In addition, the body spends a lot of energy digesting protein, compared with carbohydrates and fats. The review recommends at least 25 to 30 grams of protein at each meal. So a meal with high-quality protein helps cut down on snacking and keeps hunger in check.
How much protein intake do you really need?
The classic recommendation for a healthy adult is 0.8 grams of protein per kilogram of body weight per day. That’s the minimum amount to prevent deficiency, and not necessarily the optimal amount. However, the guidelines are changing. In January 2026, the new Dietary Guidelines for Americans raised the target to 1.2 to 1.6 grams per kilogram per day, adjusted to each person’s energy needs.
Beyond that, your needs vary with age and health:
- Healthy adults: at least 0.8 grams per kilogram per day, and 1.2 to 1.6 grams according to the new American guidelines.
- Over 65: according to the PROT-AGE group, at least 1.0 to 1.2 grams per kilogram per day, and 1.2 to 1.5 grams during illness.
- During weight loss: 1.2 to 1.6 grams per kilogram per day, and sometimes even more, depending on your medical condition and activity level.
- People who do strength training: a meta-analysis of 49 studies showed that above about 1.6 grams per kilogram per day, there is no added gain in muscle mass.
Can you eat too much protein?
Here, too, balance matters. For most healthy people, there’s no evidence of significant harm from a relatively high protein intake. However, eating too much over time can add extra calories. It can also crowd vegetables, legumes and whole grains off your plate. And when most of the protein comes from processed and fatty meat, your saturated fat intake goes up too.
People with kidney disease need to be especially careful. For example, PROT-AGE recommends that people with severe kidney disease who are not on dialysis limit their protein. In cases like these, it’s best to set the amount with your care team.
Animal or plant protein?
Animal protein sources include fish, chicken and turkey, eggs, dairy products and meat. This protein contains all the essential amino acids and is well absorbed. It’s also rich in iron, zinc and vitamin B12.
Plant protein sources, on the other hand, include legumes, soy and tofu, edamame, nuts and seeds. They also provide dietary fiber and support heart health. In the end, the healthiest approach is usually a mix of animal and plant sources.
Do you need protein powder?
No. Most people can get the protein they need from regular food. Still, protein powders are useful in a few situations: after bariatric surgery, during a period of rapid weight loss, for older adults who struggle to eat enough, and for athletes with high demands. Even then, they don’t replace a balanced diet.
Protein intake as we age
One of the key goals of modern medicine is preventing sarcopenia, the loss of muscle mass and strength with age. Muscle loss starts gradually in midlife and speeds up at an older age. Getting enough protein, combined with strength training, is one of the most effective ways to slow this process.
It’s important to understand that protein alone isn’t enough. The combination of protein and resistance training is the key to strength, independence and function as we age. I also explain the link between obesity and muscle loss in my article on sarcopenia and obesity.
Protein intake in the age of weight loss injections
With the rising use of Mounjaro, Wegovy and Ozempic, protein intake is more important than ever. These drugs sharply reduce appetite, and sometimes the total amount of food as well. In that situation, the risk of muscle loss goes up unless you make a point of eating protein and staying active.
A joint advisory from four professional organizations, published in 2025, highlights this point. According to the advisory, preserving muscle and bone mass during treatment requires strength training and proper nutrition. In other words, the message is no longer just “eat less,” but “eat right,” with high-quality protein at every meal. You’ll find practical tips in my nutrition guide for weight loss injections.
The bottom line
Protein isn’t a passing trend. It’s one of the most important components of human health. Adequate protein intake protects muscle mass, supports weight loss and increases fullness. It also improves function as we age and contributes to quality of life.
That said, protein doesn’t work alone. The best results come from combining a balanced Mediterranean diet, high-quality protein at every meal and strength training. Good sleep, stress management and personalized medical care also play a part. Finally, the better we understand the connection between protein, muscle and longevity, the more protein will become a central tool in preventive medicine. I’ve written more about that connection in my article on protein and longevity.
The information in this article is general and does not replace personal medical advice.
References
Dietary Guidelines for Americans, 2025-2030
