Do diet apps work? This is what experts want you to know

If you’re looking for ways to change up your diet, you may have considered using a dieting app to build some healthy habits and maybe lose weight. A diet app can be a helpful way to learn more about what you’re eating and make some lifestyle changes.

Dieting apps are less expensive and less time-consuming than seeing a professional dietitian or consulting a doctor, and could be a good option for those who need a hand with self-motivation (and don’t have underlying health conditions). Here’s what professionals want you to know about signing up for a diet app.

Diet apps can be a great teaching tool

There are many dieting apps out there, but they work in similar ways. Most offer food tracking so you learn more about what you eat, both in terms of quality and quantity. Weight-loss apps in particular focus on food choices, often encouraging certain foods, such as nutrient-dense, low-calorie options like fruits and vegetables, and discouraging others, such as high-calorie, low-nutrient sweets. Others allow you to track your macronutrients (i.e., the carbohydrates, proteins, and fats in each food) and other nutrition information to see for yourself where you might want to increase or reduce your intake. Many apps have food databases and barcode scanners to make the food logging aspect less arduous and potentially more fun than just writing down what you eat on a piece of paper.

One classic diet option, WeightWatchers, uses a point system in lieu of a traditional calorie counter. You have an allotment of points for the day, with the healthier, low-cal foods counting for fewer points (or none at all!) and higher-calorie foods worth more points. Newer diet app Noom uses a traffic light system that categorizes nutritious and low calorically dense foods as green (eat in abundance) and high calorically dense foods as red (eat in moderation). In our Noom review, our tester found it to be useful and easy to track and categorize the food she ate. Both WeightWatchers and Noom encourage fitness as a part of a weight-loss journey, giving calorie credit for syncing data from fitness trackers like Fitbit and the Apple Watch or fitness apps like Apple Health, or simply logging exercise sessions into their activity tracker sections.

Using an app can be educational, no matter your goal. As you log your food, you’ll get a better understanding of general nutrition, which can help you make changes when meal planning. Apps can also be helpful when learning about portion sizes, which can be difficult to visualize and even more difficult to understand within a daily calorie budget.

Dieting apps only work if they teach sustainable habits

Whether you use an app or not, studies show that most “diets” aren't sustainable long-term due to their restrictive nature, as well as the natural inclination to go in all-or-none. So if you find yourself struggling after a few months—or having some success, then returning to old habits—don’t stress. You’re not alone.

“Most 'diets' don't work because diets are a restriction of either a food group or calories,” says Jessica DeGore, RD, a Pittsburgh-based registered dietitian. “Whenever you cut out a food group, you're basically cutting down a significant amount of calories. So a lot of that weight [you lose] tends to come back after you stop following your diet.”

Smaller changes often work better in the end, if you can integrate them into your lifestyle, which you can achieve with an app, as long as you give yourself some time (and cut yourself some slack) to acclimate to them. While it may be tempting to choose the program that promises you’ll shed 10 pounds in a month, the diet that encourages you to eat more whole foods and up your daily step count may be the better option.

Diet apps require self-motivation

When making changes to your diet or lifestyle, it helps to ask yourself why you’re doing it in the first place. If you find you have a reason that’s important to you, you may be more likely to stick with the change you’re making. “With any health and wellness change the ‘why’ is really important because your ‘why’ is what's going to sustain you in that change,” says Elizabeth Gunner, RD, a New York City-based registered dietitian. “If the ‘why,’ for example, is ‘I want a flat stomach,’ that might not be as sustainable compared to somebody whose ‘why’ is ‘I want to prevent diabetes because it's something that runs in my family.’”

If you have trouble figuring out your “why,” Gunner recommends talking it through with a professional. “Some of them are deep-rooted,” she says. “We think it's just a surface-level thing, but in reality, it's deeper. A lot of times it's ‘I want to feel valued,’ ‘I want to feel loved,’ ‘I want to feel accepted,’ [or] ‘I want to feel worthy.’”

Setting a health and wellness goal as a way to truly care for yourself and not from a place of judgment can make all the difference, particularly if it’s a weight-loss goal. “I always tell my clients to come from a place of love and abundance rather than fear and lack,” Gunner says. “If you're coming from a place of actual love for yourself, like you would a best friend or a parent, then I think that's already setting you up for more success, versus the self-hatred that oftentimes we go down in order to like ourselves more.”

Dieting apps aren’t one-size-fits-all

With any new diet program you start using, an app or otherwise, think about your needs beforehand. Many diets restrict users to extremely low calorie intakes that aren’t healthy or sustainable. “A lot of apps I've seen will recommend as low as 1,200 calories per day, sometimes 1,500 calories,” DeGore says. “We recommend 1,200 calories for toddlers, so I would never recommend that for a grown adult.” Not only will this heavy restriction not be sustainable, it may do more harm than good in the long run. It can slow down your metabolism, alter your natural hunger cues, and possibly lead to food binges.

Additionally, you may have more specific nutritional needs that an app may not take into account. If you know you need a high-fiber diet for managing diabetes or low-FODMAP (for those with conditions like irritable bowel syndrome), you should find a program that takes those needs into account. Some apps cater to specific trends such as the keto diet, though it’s best to talk with a doctor or nutritionist before self-imposing such dietary restrictions.

You also just may not like the user experience of some apps, which can make them not work because you don't use them to their fullest potential. Luckily, all are free to download and most have a free version or a free trial so you can see if you like using them before signing up.

Diet apps could spell trouble for people with eating disorders

Some app users may become too focused on calorie counting or weight tracking and begin to have obsessive thoughts or guilt about consuming “bad” foods. Those folks may want to reconsider whether this kind of food diary tracking is a good idea for them in general. “Whenever we put a negative label on something or put it on a shelf, we tend to crave it more,” says DeGore. “And that kind of makes us a little crazy and food-obsessed, which I would not consider healthy behaviors.”

Those negative thoughts may include obsessing over food, having anxiety around social settings involving food, or feeling guilt or shame from “cheating” on the diet, and having them often could signal the start of disordered habits. “It happens more often than people think,” Gunner says. If you find yourself unable to stop thinking about food, your diet, or logging what you ate, she recommends talking to someone who can help, be it a therapist, dietician, or a trusted family member or friend.

Anyone with a history of disordered eating or obsessive exercise habits should steer clear of diet or calorie-counting apps, unless used under the guidance of a doctor. Additionally, if someone in your family has struggled with an eating disorder you may be at a higher risk of developing one, so proceed with caution.

Not all dieting apps are about calorie counting

If you’re simply looking to learn more about your personal nutrition, Gunner says Cronometer is a good option (available for iPhone in the App Store and Android at Google Play). This app offers the options to set custom nutrient goals and to track biometrics like blood pressure, blood glucose, and cholesterol, which may be important to some users.

If you’re looking for a weight-loss app but are worried about obsessing over your numbers, DeGore recommends apps that are less calorie-focused and more mindfulness-centered. Am I Hungry (for iPhone and Android) and Ate (for iPhone and Android) are two apps that focus on intuitive eating and building lifelong healthy habits, rather than being a fleeting weight-loss plan.