You know how it is with regular dieting—your long-lost skinny jeans make a temporary reappearance only to be retired to the back of your closet six months later. This frustrating scenario of weight cycling is all too familiar for most people.
Although decreased motivation and will-power greatly contribute to “falling off the wagon”, weight regain is also influenced by biological changes in the body in response to decreased intake of energy or calories. The main biological reason for weight regain is a slowing metabolism. A reduction in calorie intake can make the body become very efficient and work to conserve energy. Unfortunately, this means you are burning fewer calories. Loss of lean tissue (such as muscle) rather than fat mass during weight loss is also to blame for a lower metabolic rate (more on this below).
In a world where yo-yo dieting has become the norm, how does one keep lost pounds off for good?
New research carried out by a group of scientists from the Netherlands reveals that a diet higher than normal in protein may be the key to sustaining permanent weight loss (1). Seventy-two overweight and obese men and women took part in the study, which compared the effects of two reduced-calorie diets after weight was previously lost, the only difference between the diets being that one counted as high protein intake (1.2 grams of protein per kilogram of body weight per day) and the other as normal protein intake (0.8 grams of protein per kilogram of body weight per day). After six months, the group eating more protein was found to retain greater muscle mass and a higher rate of metabolism, helping to better keep that lost weight from returning.
Previous studies investigating the effect of energy-restricted, high protein diets on weight maintenance have reached similar conclusions (2). The fat-fighting power of protein lies in its ability to keep energy expenditure elevated as well as curb hunger despite reduced calorie intake.
Rev Up Your Metabolism with Protein
Energy expenditure, or the number of calories burned by the body, is greatly influenced by basal metabolic rate (BMR), which is the amount of energy, or rate of metabolism, required to support basic body functions when your body is at rest.
The greatest contributor to BMR is fat-free mass. Fat-free mass is largely made up of muscle, which is very energy demanding. Even when no work is being performed (such as when you are sleeping), muscle requires energy just to exist. Muscle cells and their components are constantly using calories to rebuild what is broken down during normal protein turnover. A higher protein diet not only increases energy-demanding protein synthesis and turnover, but has also shown to better preserve muscle during caloric restriction (1, 2). Keeping muscle mass and turnover rates high results in a higher BMR, faster metabolism, and greater energy expenditure.
The thermic effect of food (TEF) is another factor that affects energy expenditure and refers to the amount of energy needed to break down, absorb, and digest food. The TEF differs between nutrients, with protein requiring more calories for digestion and metabolism than both fat and carbohydrate combined. Specifically, 0 to 3 percent of the calories obtained from fat are used for fat digestion, 5 to 10 percent of calories from carbohydrate are used for carbohydrate digestion, and 20 to30 percent of calories from protein are used for protein digestion (2). This means that protein requires a substantial amount of calories for the body to metabolize and use it compared to the other macronutrients. Simply by eating more protein in place of carbohydrate or fat, a person will burn more calories.
Feel Fuller, Longer with Protein
Successfully committing to a reduced calorie diet can be difficult when you are bombarded by cravings and hunger pangs. Ravenous hunger will only encourage overeating and weight regain. Research has shown higher protein diets to be superior to low or standard protein diets in causing a feeling of fullness, thereby leading to lower calorie intake (2). A reduced calorie diet will lead to greater use of existing fat stores, as a person quickly burns through the energy provided by the food they consume, as well as the carbohydrate stored in the body (glycogen). This increased reliance on fat for fuel has been suggested to reduce appetite.
Protein may also boost satiety by sending hormonal messages to the brain signaling fullness. When protein is eaten, sensors located in the gut are activated. Hormones such as glucagon are released, sending a message to the brain saying, “I’m full!” (3).
Sustaining weight loss over the long term is challenging but not impossible. A higher protein diet offers numerous metabolic advantages that will not only help a person lose weight, but may also prevent regaining pounds, or worse, surpassing your starting weight.
Isagenix offers a variety of convenient and delicious higher protein meals and snacks that can aid weight maintenance efforts. Incorporating these Isagenix snacks and meal replacements in your reduced calorie diet will not only help you get into those skinny jeans, but stay in them, too.
1) Soenen S, et al. Normal Protein Intake Is Required for Body Weight Loss and Weight Maintenance, and Elevated Protein Intake for Additional Preservation of Resting Energy Expenditure and Fat Free Mass. J Nutr. 2013 Feb 27. [Epub ahead of print]
2) Westerterp-Plantenga MS, et al. Dietary protein – its role in satiety, energetics, weight loss and health. Br J Nutr. 2012 Aug;108 Suppl 2:S105-12. doi: 10.1017/S0007114512002589.
3) Belza A, et al. Contribution of gastroenteropancreatic appetite hormones to protein-induced satiety. Am J Clin Nutr. 2013 Mar 6. [Epub ahead of print]