Apps that promise to help you eat healthier are hugely popular, with millions of downloads. And many make the same promise: by tracking what you eat and calculating your optimal calorie intake, they will help you to lose weight.
And according to research, they might.
These apps operate more or less like this: First, you enter your height and weight, and set some goals, like losing weight or eating a certain amount of protein each day. Then, you log every item of food and every exercise you do. At the end of the day, the app provides feedback on how you did that day in relation to your goal, and saves the information so you can see your progress over time.
Tracking your food intake can be very helpful for weight loss, said Dr. Arya Sharma, a professor of medicine at the University of Alberta who specializes in obesity.
“In terms of any kind of behaviour change, there is a key principle and that key principle is self-monitoring,” he said. Setting goals, keeping track of your progress and getting feedback on what you’re doing is an important part of changing your behaviour, he added.
Studies have shown that keeping a “food diary” aids in sustained weight loss. A recent study in the journal Obesity found that people who logged their food more frequently lost more weight. A 2008 study also found that keeping frequent food records was associated with greater weight loss among participants.
Just writing down what you eat, and knowing that you have to record it, can be a powerful reminder to make healthy choices, he said. Say you passed a plate of cookies in the office. “That simple act of saying, ‘OK, but now I need to record and I need to remember it,’ might actually make you think twice,” he said.
“Something that you might not have been paying a lot of attention to is now suddenly something that you have to pay a little bit of attention to,” he said.
However, Sharma doesn’t recommend setting a weight loss target, as these apps often ask you to do.
“Losing weight is not a behaviour,” he said. “I don’t have control over that but I do have control over what I can do. Eating 1,500 calories a day is a behaviour. Now does that mean I’m going to lose weight? Maybe, maybe not. How much weight am I going to lose? I don’t know. Everybody’s different.”
Registered dietitian Andrea D’Ambrosio is not enthusiastic about calorie-counting apps as a weight loss tool and they’re not the first thing she recommends in her practice, she said, though some people might find them helpful.
“It’s such an individual choice and what works for someone might not work for the next person,” she said.
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The goals and calorie targets it sets are based mostly on your height and weight, she said, and so won’t be accurate for everyone. Practically speaking, it can also be time-consuming to log every ingredient in a home-cooked meal, she said, or hard to remember whether you ate one or one-and-a-half cups of rice with lunch.
That means that the calorie counts would be off — sometimes way off. A recent study found that people were forgetting to log about 18 per cent of the items they consumed in a day, especially the most calorie-dense foods.
“Most of the inaccuracy in those apps actually comes from the data that people put in, rather than from the actual app itself,” Sharma said.
D’Ambrosio also worries that calorie apps focus too hard on “gamifying” eating, at the expense of developing a balanced approach to nutrition. “The actual tracking can be very triggering for people who have had an eating disorder or who have disordered eating,” she said. “They’re already fixated on food, they’re already thinking about calories and obsessing about it. And then asking them to track on a tracker is just not a good idea.
“It’s great to have a health focus or an awareness on how we can get more fruits and vegetables and balance our plate.” But that’s not the same as counting calories, she said, though an app or other food tracker can help you be more generally aware of your habits.
Then, there’s the problem of sticking with it. “It can be frustrating tracking weights and it leads people to often stop their behaviour changes if they don’t see the scale move,” D’Ambrosio said.
“Most people don’t want to continue tracking even if they do for a short period of time. It’s just not something that’s enjoyable. It can be very time-consuming as part of a lifestyle, and if we can’t continue doing something, the sustained weight loss can be a challenge.”
When his patients stop tracking their food, Sharma said, they often start gaining weight back.
“That’s been shown over and over again. When people monitor these things and pay more attention to certain behaviours, then those behaviours change,” he said.