When talking about diet after bariatric surgery, doctors always emphasize to their patients that “protein intake must be a priority”. Although this recommendation is always at the top of the dietary guidelines, little research has been done to determine the correlation between postoperative protein intake and fat loss. A recent study published in Surgery for Obesity and Related Diseases confirms that this recommendation is more than mere rhetoric. Protein intake is critical to achieving healthy weight loss after surgery. First, let’s get to know what is de-fatted weight? Our body composition can be divided into two parts: fat and all other substances left over. The rest of the body, excluding fat, is called fat-free weight, also known as lean body mass, and includes internal organs, bones, muscles, water and connective tissue. In the process of weight loss, the goal is to lose body fat while retaining the fat-free weight. One of the most important ways to retain fat-free weight, especially muscle tissue, is to provide the right amount of protein, even on a calorie-restricted diet. What results did the study produce? The study evaluated daily protein intake after laparoscopic sleeve gastrectomy (LSG) and the correlation between protein intake and loss of decompensated body weight. A total of 77 patients who underwent LSG and were followed up for 12 months postoperatively were included in the study. Data were collected on body composition, 3-day meals, food tolerance and exercise before and after surgery, and at 3, 6 and 12 months after surgery. The results found that: 1. 13.3%, 32.5%, and 39.7% of patients were able to ensure a daily protein intake of ≥60 g at March, June, and December postoperatively, respectively; 2. fat loss significantly improved at June postoperatively and stabilized at December postoperatively; and 3. there was a significant correlation between a daily protein intake of ≥60 g and less fat loss postoperatively. This study supports the idea of consuming ≥60 g of protein per day after LSG to prevent the loss of defatted weight. Finally, let’s learn about sources of high-quality protein and their benefits! When you’re choosing protein food sources, high protein doesn’t always mean low fat. Always be aware of the amount of saturated fat in your food choices. Some of the better sources of protein include poultry (skinless), fish, lean meats (lean meat from pigs and cows), eggs, low-fat cheese, skim milk, plain yogurt, and a variety of beans. At the same time, it is a great way to share recipes with other bariatric surgery patients in order to ensure that eating after surgery is fun. In addition to retaining fat-free weight, especially muscle tissue, protein can provide many other benefits. It promotes post-operative wound healing, maintains healthy hair, nails, skin and bones; helps the body form the enzymes and hormones it needs to maintain normal physiological function, supports a healthy weight loss metabolism, controls hunger between meals, and more. Therefore, in any case, for healthy weight loss and nutritional needs of the body, bariatric surgery patients need to follow the dietary guidelines provided by their doctors to ensure protein intake.