"Eat less and move more." Oh, such simple advice, but is maintaining a healthy weight really that simple? We live in an era of nutritional misinformation and opinions galore. These days, it seems that everyone feels qualified to offer expert advice on diet, exercise and weight loss. With rising obesity rates all around the world, we are constantly searching for approaches to better manage our weight and our health.
For decades, the main strategy for losing weight has been to cut back on calories. what nutritionists call an “energy-restricted diet.” Although this often works in the short term, it rarely produces long-term success. It backfires because it can lead to greater feelings of hunger after the weight is lost, more obsessive thoughts about food and eating, and a greater risk of overeating due to negative emotions and stress. These complicate the bodily mechanisms that control appetite and partly explain why most people regain the weight in the long term.
Other types of restrictive diets, such as the popular high-fat, no-carbohydrate ketogenic regimen, have some of the same problems. Like low-calorie diets, they are difficult to follow over a long period of time, which can lead to feelings of frustration and failure. The challenge for researchers has been to find a strategy that is not restrictive and that can reduce feelings of hunger and improve eating habits and overall health without causing some of these negative side effects.
The answer, it turns out, may be a diet constructed from healthy foods that are especially satiating; that is, foods that create feelings of fullness and satisfaction. Nutrition researchers have discovered many such foods, which improve appetite control and decrease food intake, conditions necessary for sustained weight loss. A satiating diet includes foods that are high in protein (such as fish), high in fiber (whole grains, for example) and high in fruits and vegetables. It contains healthy fats, such as the polyunsaturated fats found in avocados, and includes dairy products such as yogurt. Perhaps surprisingly, it might also include capsaicin, the substance that makes jalapenos and other peppers so hot.
What’s so special about these foods is that each of them possesses specific characteristics that benefit our health either by decreasing hunger, reducing body fat, lowering blood sugar, improving blood pressure or increasing metabolism. For instance, yogurt contains protein, calcium and lactic acid bacteria, which are the live and active bacteria that help with the growth of good bacteria in the gut. A healthy gut microbiome has been found to help control body weight and improve other aspects of health. In some specific populations, such as people with obesity or type 2 diabetes, these food components have been found to help control appetite and positively impact overall health.
But what if we took all of these key components and combined them into one diet as an approach to manage weight? That’s exactly what our team did at Université Laval in Quebec City, Canada. As a nutritional researcher there, I have spent years trying to understand how what we eat affects appetite, body weight and metabolic health over the life span. We took foods containing most of these components and created what we called a "highly satiating diet."
In a 2017 study, 34 obese men were placed on this regimen, which was 20 to 25 percent protein, for 16 weeks. Another 35 obese men followed a standard diet: 10 to 15 percent protein, and based on Canadian national guidelines for healthy eating. The men who followed the highly satiating diet significantly reduced their weight and body fat and had greater feelings of fullness compared to men who followed the standard diet. They were also better able to stick to the highly satiating diet: only 8.6 percent quit the diet, compared to 44.1 percent of the men following the standard diet.
These are very promising findings, but is it possible to maintain the weight lost over the long term with this strategy? What about metabolic and mental health; can it prevent cravings and negative emotions? What about the role of other lifestyle factors on body weight such as sleep, physical activity and prolonged sitting? We don't have the answers yet, but we are planning further studies that we hope will address these questions. If the highly satiating diet proves to have the benefits we saw in our study and if it proves to be sustainable, it could be a realistic and potentially powerful dietary solution to the problem of weight control.