By Laura Smith
Body weight has become an increasingly important health issue in our society due to its association with the risk of developing multiple diseases including cardiovascular disease, diabetes, and cancer, among others. As a result, many individuals are seeking effective, sustainable strategies to lose weight. Derived from the scientific concept that an individual must burn more calories than they consume to lose weight, many weight loss interventions focus on the quantity of food that one consumes and not the quality, restricting individuals to a specific number of calories per day.
While there is substantial research supporting low-calorie diets as a weight loss intervention that effectively reduces disease risk factors, there have also been negative outcomes associated with the restrictive diet. Due to the focus on calories alone, many individuals continue to eat empty-calorie foods such as processed snacks and desserts which lack nutrients including fiber, a nutrient associated with satiety and weight control that can be found in whole grains, fruits, and vegetables . Strict calorie limits also make it difficult to stick with the diet causing some individuals to revert to their previous dietary habits and regain lost weight. Additionally, calorie restrictive behaviors raise concern for the development of disordered eating patterns such as binge eating and psychological issues including negative body image and depression.
These potential negative outcomes have led researchers to ask if dietary interventions focused on food quality and healthy eating behaviors instead of calorie counting could produce weight loss and improve disease risk factors. A recently published study in the Journal of the American Medical Association suggests that this approach can work. In this study, conducted by Dr. Christopher D. Gardner and colleagues at Stanford University, 600 overweight and obese adults were randomized to a healthy low-fat diet or a healthy low-carbohydrate diet and monitored over a 12-month period for dietary intake and weight change. During this time, study participants received 22 counseling sessions, led by registered dietitians. In these sessions, patients were instructed on how to avoid high-fat foods (when a participant followed a “healthy” low-fat diet) and high-carbohydrate foods (when a participant followed a “healthy” low-carbohydrate diet). These sessions also emphasized consumption of a quality diet that maximized intake of fruits and vegetables; minimized consumption of foods containing added sugars, refined flours and trans fats; and focused on whole foods that are minimally processed and nutrient dense.
Unique to this study is the emphasis on cultivating individualized and sustainable dietary changes. Instead of giving hard limits on calorie, fat and carbohydrate consumption, participants were asked to begin the intervention consuming 20 grams per day of either total fat or carbohydrate for the first eight weeks. After this, they were allowed to increase consumption of these macronutrients incrementally until they reached the lowest level they felt they could maintain. This method encourages participants to control the amount they consume based on satiety and fullness and not by how many calories they had left. According to the New York Times, the participants were relieved that they did not have to focus on calories and felt that this approach changed their relationship with food.
After 12-months, the healthy low-fat and healthy low-carbohydrate diets produced similar weight loss (an average of 11.6 lbs and 13.2 lbs, respectively) and reduction in caloric intake (20.1% and 23.6% of baseline, respectively) despite the intervention lacking a calorie restrictive component. This study suggests that neither a healthy low-fat or low-carbohydrate diet is superior for weight reduction. In addition to weight loss, participants experienced reductions in disease risk factors including blood pressure and blood glucose. It is important to note that like other dietary intervention studies, participant weight loss was variable ranging from weight gain to 50 lb weight loss. There could be a number of explanations for this, including lack of readiness to change eating behaviors.
While findings from this article continue to support the notion that reducing calorie intake is associated with weight loss, it offers an alternative approach to stressing over calorie counts and shifts the focus where it should be: quality foods and a healthy relationship with food. Maybe you don’t need that calorie counting app after all!
If you are interested in dietary changes for a healthy weight, UNC’s campus health has a lot of great resources including a registered dietitian whois available for counseling in weight management!
Peer reviewed by Natalie Rebolledo Fuentealba