Dieting? Studies weigh in on opportunities and risks

Virtual conference presents progress and pitfalls in understanding the best way to lose excess weight

Many of us are eating differently during the COVID-19 pandemic, and some are taking the stay-at-home lifestyle as an opportunity to work on weight loss goals. Get the latest research findings on fad diets, losing weight and healthful eating at NUTRITION 2020 LIVE ONLINE, a virtual conference featuring leading nutrition experts from around the world.

NUTRITION 2020 LIVE ONLINE is hosted by the American Society for Nutrition (ASN), the preeminent professional organization for nutrition research scientists and clinicians. ASN's flagship meeting, Nutrition 2020, was canceled due to the impacts of COVID-19. Attend the meeting for free online or contact the media team for more information.

Dieting risks

Is your weight loss diet giving you enough nutrients?

Micronutrients are important for keeping your body healthy and warding off disease. In a year-long randomized controlled trial, researchers found that 54 people following one of two diets--a low-carbohydrate diet or a high-fiber, bean-rich diet--showed similar results in terms of weight loss but were deficient in some micronutrients. While nutrient content varied between the two diets, participants in both groups consumed less than the recommended daily amount of vitamin D, vitamin E, calcium, magnesium and copper.

Neal G. Malik, California State University, is the presenting author. This research will be presented as a virtual abstract presentation beginning June 1 at 12 p.m. EDT.

When healthy eating becomes an obsession

A new study suggests weight-loss diets may go hand-in-hand with orthorexia nervosa, a potentially damaging obsession with healthy eating. An internet survey of more than 400 college students found more than three-quarters of respondents who reported following a weight loss diet also showed signs of orthorexia, compared to less than 40% among those who were not dieting. Those following a weight loss diet also showed a much higher risk for other eating disorders.

Zhiping Yu, University of North Carolina at Chapel Hill, is the presenting author. This research will be presented as a virtual abstract presentation beginning June 1 at 12 p.m. EDT.

Looking beyond food

Can gut microbes help--or hinder--weight loss?

While the microbes living in and on our bodies play a big role in our health, little is known about how they influence weight loss efforts. New research suggests that the type of bacteria in a person's gut may help predict their likelihood of weight-loss success. Out of 36 people participating in a six-month weight loss program, the 12 participants who succeeded in losing the targeted amount of weight (5% weight loss) showed lower concentrations of certain bacteria and higher concentrations of others at baseline compared to participants who did not lose weight. The findings suggest gut microbes may influence weight loss by affecting how the body processes food, researchers say.

Moira K. Differding, Johns Hopkins Bloomberg School of Public Health, is the presenting author. This research will be presented as a virtual abstract presentation beginning June 1 at 12 p.m. EDT.

Exercise brings no weight loss boost compared to diet alone

A study involving 383 overweight adults found that following a calorie-restricted diet resulted in roughly the same amount of weight loss regardless of a person's level of physical activity. After one year of limiting their intake to 1,200-1,800 calories per day, participants lost just over 20 pounds on average, but the amount of weight lost was not significantly different among participants who exercised an average of 1.5 hours per week compared to those exercising nearly 4 hours per week. The researchers also found that participants' level of physical activity did not affect their ability to keep their calorie and fat consumption within bounds.

Carli A. Ligouri, University of Pittsburgh, is the presenting author. This research will be presented as a virtual abstract presentation beginning June 1 at 12 p.m. EDT.

Nutrition tech

How reliable are commercial nutrition apps?

Researchers examined how calories and nutrients are calculated in two commercial nutrition apps--CalorieKing and MyFitnessPal--compared to a reference database used by scientists, the University of Minnesota Nutrition Coordinating Center Nutrition Data System for Research (NDSR). Overall, the apps were similar to the NDSR in counting calories and nutrients for the 50 most commonly consumed foods, with a few exceptions. MyFitnessPal was less reliable in its assessment of total fat and fiber intake for all foods, and was especially unreliable when it came to calculating calories, carbohydrates and fiber content of fruits. This variability underscores the need to compare nutrition apps with validated data sources if they are to be used in research and practice, researchers say.

Annie W. Lin, Northwestern University, is the presenting author. This research will be presented as a virtual abstract presentation beginning June 1 at 12 p.m. EDT.

Personalized weight loss program does not bring added confidence

Researchers are exploring whether a weight loss diet can be made more effective by accounting for how a person's body responds to specific foods. Early results from the three-month data involving 75 participants suggest this personalized approach has no effect on how people perceive their ability to resist overeating compared to a one-size-fits-all diet. The researchers plan to continue the study to examine how a personalized diet might affect participants' confidence or actual weight loss in the longer term.

Lu Hu, New York University, is the presenting author. This research will be presented as a virtual abstract presentation beginning June 1 at 12 p.m. EDT.