Diet and Physical Activity Apps: Perceived Effectiveness by App Users

Background Diet and physical activity apps are two types of health apps that aim to promote healthy eating and energy expenditure through monitoring of dietary intake and physical activity. No clear evidence showing the effectiveness of using these apps to promote healthy eating and physical activity has been previously reported. Objective This study aimed to identify how diet and physical activity (PA) apps affected their users. It also investigated if using apps was associated with changes in diet and PA. Methods First, 3 semi-structured focus group discussions concerning app usability were conducted (15 app users and 8 nonusers; mean age 24.2 years, SD 6.4), including outcome measures such as motivations, experiences, opinions, and adherence. Results from the discussions were used to develop a questionnaire. The questionnaire, which contained questions about behavior changes, app usage, perceived effectiveness, and opinions of app usability, was answered by 500 Norwegians, with a mean age of 25.8 years (SD 5.1). Results App users found diet and PA apps effective in promoting healthy eating and exercising. These apps affected their actions, health consciousness, and self-education about nutrition and PA; and were also a part of their social lives. Over half of the users perceived that apps were effective in assisting them to eat healthily and to exercise more. Diet apps were more effective when they were frequently used and over a long period of time, compared to infrequent or short-term use (P=.01 and P=.02, respectively). Users who used diet and PA apps, perceived apps as more effective than users who only used one type of app (all P<.05). App users were better at maintaining diet and PA behaviors than nonusers (all P<.05). Young adults found apps fun to use, but sometimes time consuming. They wanted apps to be designed to meet their personal expectations. Conclusions App usage influenced action, consciousness, self-education about nutrition and PA, and social life. It facilitated maintaining a healthy diet and exercising more. Diet and PA apps of the future can be further strengthened by being tailored to meet personal needs.

I did this prior to the last 12 months, but not in the last 12 months I did this prior to the last 12 months, as well as in the last 12 months.
I did not do this prior to the last 12 months, but I started to do it in the last 12 months.
I did not do this prior to the last 12 months, nor in the last 12 months.
I do not know I paid attention to calorie information.
I chose low-fat products instead of ordinary products. I chose mineral water instead of sweetened beverages.
I cooked at home instead of buying ready-made meals.
I searched for information about food or cooking on the Internet or in books or magazines.

3.
Here are statements about getting fit. Please choose the answers that fit you the best. I did this prior to the last 12 months, but not in the last 12 months I did this prior to the last 12 months, as well as in the last 12 months.
I did not do this prior to the last 12 months, but I started to do it in the last 12 months.
I did not do this prior to the last 12 months, nor in the last 12 months.

App questions Section 1: diet apps
Here is an example of a diet app that enables users to track dietary intake, and gives relevant information about food and diet.
12. Have you used a diet app (on a mobile phone, tablet, or computer) during the last 12 months?
a. Yes, I have used a diet app during the last 12 months, and I am currently using it.
b. Yes, I used a diet app during the last 12 months, but I am not currently using it. Please think about the period that you use/used the diet app, and answer the following two questions.
14. How often did you use the diet app during the first month after you started using it?
More than once per day It is easy for me to understand how the diet app works.
It is time consuming for me to use the diet app.
It is easy for me to get information from the diet app.
It is boring to use the diet app.
It is easy for me to reach my goal by using the diet app.
17. What is your main goal when using diet apps?
To track my calorie intake To check nutrients in my food To check information because I have allergies, celiac disease, or other food-related health issues.
To get an overview of my food consumption Using the app is …. compared to specific diets.
Using the app is …. compared to weight-loss courses.
Using the app is …. compared to learning cooking or healthy food choices from TV, books, or the Internet.

Section 2: physical activity app
Here is an example of a physical activity app that enables users to track physical activity throughout the day, or track physical activity during specific events such as running, biking, or aerobics, and gives relevant information about exercise.

21.
Have you used a physical activity app (on a mobile phone, tablet, or computer) during the last 12 months?
a. Yes, I have used a physical activity app during the last 12 months, and I am currently using it.
b. Yes, I used a physical activity app during the last 12 months, but I am not currently using it. Please think about the period that you use/used the physical activity app, and answer the following two questions.
23. How often did you use the physical activity app during the first month after you started using it?
More than once per day It is easy for me to understand how the physical activity app works.
It is time consuming for me to use the physical activity app.
It is easy for me to get information from the physical activity app.
It is boring to use the physical activity app.
It is easy for me to reach my goal by using the physical activity app.
26. What is your main goal when using the physical activity app?
To track my physical activity Using the app is …… compared to consulting personal trainers.
Using app the is …… compared to joining sports clubs.
Using the app is …… compared to using private exercise rooms.
30. How did using the physical activity app change your frequency of exercising in number of days? Choose the sentence that fits you the best and fill in the number of days. After using the physical activity app, I exercised__________ less days per week than before. After using the physical activity app, I exercised__________ more days per week than before. The number of days that I exercised did not change.
31. How did using the physical activity app change the number of hours that you exercised? Choose one sentence that fits you the best and fill in the number of hours. After using the physical activity app, I exercised__________ hours less per session. After using the physical activity app, I exercised__________ hours more per session. The number of hours that I exercised did not change.