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Columns: Research Bites

Research Bites

Yoke, Mary M. Ph.D., M.A., M.M., FACSM

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doi: 10.1249/FIT.0000000000000413
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Have you ever used a nutrition app? If so, did you find it helpful? In a 2017 article titled “Controlling Your “App”etite: How Diet and Nutrition-related Mobile Apps Lead to Behavior Change,” researchers at Brigham Young University (1) examined whether use of such apps resulted in actual changes in dietary behaviors. The research team also was interested in which health behavior theories and theoretical constructs (characteristics or ideas), if any, were used in popular nutrition-related apps.

To explore these questions, a survey was given to 217 participants via the Web-based data collection service Amazon Mechanical Turk. An advantage of using this public electronic service is that the type of participant who responds tends to be the same type of person who might use a health app. Participants in this study were mostly in their 20s or 30s, had some college education, and were 83.9% white and 55.8% female. Participants had to have used a diet or nutrition app in the past 6 months to be included in the sample. Survey questions included participants’ age, race, education, use of nutrition-related apps in the past 6 months, likability of the apps, and subsequent changes in their dietary behaviors. In addition, survey questions asked about constructs from three main health behavior theories: Social Cognitive Theory, Theory of Planned Behavior, and the Health Belief Model. Constructs from the theories included self-efficacy, subjective norms, attitudes, intentions, goal-setting, and perceived benefits.

What did the survey participants report? Responses were positive regarding increased participant motivation to eat healthfully as a result of app use. Participants indicated that they had more self-efficacy and more confidence in their ability to choose healthy foods, and that the frequency and consistency of healthy eating increased. Goal setting was improved and goal achievement was enhanced as a result of app usage. In short, healthy eating behavior changes resulted!

Regarding theory-related questions on the survey, the research team found that ease of app use, subjective/perceived norm, intention, attitude, and perceived benefits were all important in the decision to use a nutrition-related app. As a result, behavioral theory, app engagement, app use, and education were all associated with healthy behavior change. One limitation: it should be noted that the results may not be similar for everyone. The participant sample was relatively homogenous — young, white, educated, and lacked racial and ethnic diversity.

The take-home message? Nutrition- and diet-related apps can be an important tool in the challenge to help the general public do what they say they want to do. Health/fitness professionals might do well to recommend apps that use behavioral theories, are easy to use, and that focus on the development of self-efficacy, knowledge, positive attitudes, improving motivation, and goal-setting strategies.


Many studies show that maintenance of a healthy weight after weight loss is a greater challenge than losing weight in the first place. In other words, most individuals tend to gain their weight right back within 6 to 12 months of meeting their weight loss goals. This phenomenon can lead to discouragement, feelings of failure, higher levels of weight regain, yo-yo dieting, and negative health consequences.

In a recent review of the literature (2), Montesi et al. identified studies that analyzed factors associated with long-term maintenance of weight loss, defined as the intentional loss of at least 10% of body weight and maintenance of that weight loss for at least one year. The authors were curious about the characteristics of individuals who were able to achieve long-term weight loss, and what the important influencing factors might be. As may be expected, successful strategies employed by participants in multiple studies included daily physical activity for at least an hour, the consumption of a low-fat, low-calorie diet, eating breakfast daily, monitoring weight regularly, using a variety of behavioral techniques to stay the course, and staying consistent across weekdays and weekends. It also helped if participants were not prone to depression and disinhibition (impulsivity). Individuals with a strong internal locus of control (meaning a belief in one’s own ability to have self-control when tempted by environmental cues such as mouth-watering television ads) were more likely to lose weight and maintain weight loss than those who were easily swayed by external cues and circumstances.

So what can health/fitness professionals do to promote weight loss maintenance? Evidence exists showing that an extended-care model of treatment is helpful. This can mean offering group support sessions twice per month for as long as a year after successful weight loss. Such face-to-face programs can emphasize daily self-weighing and the promotion of self-regulatory behaviors (e.g., keeping disruptive emotions in check), as well as providing essential social support. Because it is well known that regular physical activity is key for weight maintenance; fitness professionals will want to focus on providing activities that are perceived as pleasurable by participants struggling with their weight. It’s important to note that strategies for weight maintenance are not necessarily the same as those used for weight loss.

In this review, the authors recommend the involvement of a multidisciplinary team when working with clients in the weight loss maintenance phase. Such a team would include dietitians, exercise physiologists and fitness professionals, health educators, behavioral scientists and/or psychologists, and physicians. In addition, because clients struggling with weight loss maintenance generally need significant lifestyle modification, the authors suggest the involvement of a trained “lifestyle counselor” who works closely with other multidisciplinary team members.


What is nudging? Nudging was popularized in a 2009 book by Thaler and Sunstein (3). Basically, a nudge is a construct in behavioral science that means providing indirect suggestions and positive reinforcement to influence a person’s decisions and behavior. A true nudge does not forbid any options and does not require a person to comply. For example, according to Thaler and Sunstein, “putting fruit at eye level counts as a nudge, whereas banning junk food does not.” A nudge increases the likelihood that a person will make a particular choice, and an appropriate nudge can help a person act in their own best interest.

Could the concept of nudging be used to help people eat more vegetables in a self-serve setting? Researchers in Denmark (4) aimed to compare three different nudging strategies on vegetable consumption at a self-serve food buffet. The three strategies were priming, default choice, and perceived variety. Priming, the first approach, involved making the buffet and the food environment green with leafy plants around and on the buffet, fragrant herbs, and using green serving bowls. The default choice was a premade, preportioned salad in individual bowls placed in two locations on the buffet. The perceived variety approach involved the same ingredients and same portion sizes as the default option, except that participants were to assemble the ingredients on their plates themselves. Eighty-eight participants were randomized into one of the three nudge approaches, as well as a control serving, in a crossover design.

What were the results? The three different nudge strategies produced different findings. Both the priming strategy and the perceived-variety strategy resulted in less total food consumption, mostly because participants decreased the amount of chili they selected (chili was the main protein source). The default strategy, however, significantly and independently increased the vegetable intake compared with the control serving by a mean of 45 g. The authors of the study concluded that all three nudge techniques in fact promoted an overall healthier meal composition because the goal was to increase vegetable intake — an important public health goal. Other factors that may have influenced healthier meal composition were the use of transparent salad bowls and the order of the foods presented on the buffet (placing vegetables first and making them easy to reach are other nudge techniques).

The authors discussed potential study limitations, which include the fact that the buffet environment (in a campus lab) was unfamiliar, and that participants knew their choices would be weighed and measured; these contingencies may have caused them to eat less overall. Even so, nudging seems to be a promising tool for shaping behavior. To facilitate eating more veggies and possibly reduce total calories consumed from a given meal, think green (serving dishes, leafy garnishes, and plants) and consider preportioning vegetables before serving, thus ensuring an appropriate serving size.

To learn more about this column, check out this video with Associate Editor Mary M. Yoke, Ph.D., M.A., M.M., FACSM.


1. West JH, Belvedere LM, Andreasen R, Frandsen C, Hall PC, Crookston BT. Controlling your “app”etite: how diet and nutrition-related mobile apps lead to behavior change. JMIR Mhealth Uhealth. 2017;5(7):e95. Available from: https://doi:10.2196/mhealth.7410.
2. Montesi L, El Ghoch M, Brodosi L, Calugi S, Marchesini G, Dalle Grave R. Long-term weight loss maintenance for obesity: a multidisciplinary approach. Diabetes Metab Syndr Obes. 2016;9:37–46.
3. Thaler RH, Sunstein CR. Nudge: Improving Decisions About Health, Wealth, and Happiness. New York (NY): Penguin Books; 2009.
4. Friis R, Skov LR, Olsen A, et al. Comparison of three nudge interventions (priming, default option, and perceived variety) to promote vegetable consumption in a self-service buffet setting. PLoS One. 2017;12(5):e0176028. Available from:

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