This is an excerpt from NSCA's Guide to Sport and Exercise Nutrition-2nd Edition by NSCA -National Strength & Conditioning Association & Bill I. Campbell.
By Marie A. Spano
The basic programs that are free and that allow people to track their food intake can help an athlete stay within a certain calorie or macronutrient range. Many are free, although some start off free with paid upgrades. Because of advances in technology, the fact that over three-quarters of the U.S. population own a smartphone, and the convenience of smartphones compared with computers—tracking by mobile phones has taken over from web-based programs. Many software programs have benefits, aside from just calculating calorie intake, to keep users engaged, such as charting changes in weight over time, comparing calories burned through physical activity with dietary intake, and providing sample diets for specific calorie levels (1,200, 1,500, 1,800, 2,000, 2,200, and so on).
Smartphone apps are a cost-effective way to promote healthy eating and weight loss. But only a modest number of randomized controlled trials have examined the effectiveness of smartphone apps for weight loss, and none has used athletes. From the research to date it appears that the decrease in BMI from using these apps is modest (10). Although some apps rely on self-entered data from users, which may be incorrect, the accuracy of nutrition measurements on mobile devices is generally good (9).
Despite the upside of food-tracking apps, keep in mind that all rely on the user to produce an accurate log of the type and amount of food consumed. Also, without guidance, consumers need to have a basic understanding of macronutrients and calorie needs. Many programs also have preset macronutrient goals that users need to adjust based on their own needs, which requires an in-depth understanding of nutrition. The best approach is to work with a sport nutrition professional who can help the consumer adjust macronutrients and calories after careful consideration of the person’s weight history, goals, food preferences, eating habits, and factors that influence health, athletic performance, and recovery.
Although food tracking can be helpful for many consumers, research suggests that tracking can do more harm than good in those with history of an eating disorder or at risk for an eating disorder. In one study examining the use of the app MyFitnessPal in those with eating disorders, 73.1% of participants said that MyFitnessPal contributed at least somewhat to their eating disorder, and 30.3% said that it contributed very much to their eating disorder. In addition, the more likely a person was to report that usage of MyFitnessPal contributed to their eating disorder, the more likely it was that the person had eating disorder symptoms. Because this study is retrospective and relied on self-reported data, it cannot be used to say that MyFitnessPal causes symptoms of an eating disorder (16). Another study in men found nearly 40% of users perceived MyFitnessPal as a factor contributing to their disordered eating symptoms to some extent. MyFitnessPal users also reported greater psychosocial impairment than nonusers (17). Yet another study with 493 college students found that fitness tracking was uniquely associated with eating disorder symptomatology after adjusting for bingeing and purging behavior in the past month as well as gender (26). In conclusion, it may make sense to screen people for eating disorder symptoms before suggesting they use a calorie-tracking app.