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Diet App Development: How to Build a Weight Loss App

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Anastasia Osypenko
Market Researcher

Millions of people go on diets and set weight-loss resolutions every year. For many, it has even become a mundane part of their lives: 45 million Americans are struggling to achieve their goal weight and diet on a regular basis. The same concerns are apparent in many other countries: 13 per cent of Australians aged 15 and over reported being on a diet while 38 per cent of adults in the UK admitted a desire to lose weight.

Some people gave up on the whole idea and inspired the #donewithdieting movement, blaming businesses for taking advantage of unhealthy weight-loss standards. However, there are still thousands of dieters eager to reach their weight goals.

Appearance issues alone aren't the only motivation for people who diet. Medical research shows the benefits of moderate weight loss, which includes a lower risk of chronic diseases. We can see the industry increasingly shift towards healthy weight loss. The whole approach has changed from just getting in shape to developing sustainable eating patterns and a holistic, whole-body and mind approach. Concentrating on overall health has become the main challenge for any diet-related business.

How do diet apps approach this encompassing approach to health and which apps currently exist?

Let’s take a look at how mobile programs for weight loss and maintaining a particular diet work, what their weak spots are, and the next top features that should be included.

The Many Types of Nutrition App

We described the phenomenon of self-monitoring in our article on healthcare wearables; people get obsessed with food journaling, and not only for the purpose of weight loss. A multitude of reasons stands behind this logging habit including the fact that people are more likely than ever to keep track of their wellbeing and plan their meals accordingly to how they feel when they are given the tools to do so. Plus, those who are transitioning to a certain diet need a journal to make sure they’re on the right track.

An array of other aspects can be covered in a fitness and diet app. For instance, plant-based eaters often need tools to control their nutrient intake, pregnant women need specific nutritional assistance, people diagnosed with diabetes or with some eating disorders need help to control their eating habits. At its core, a diet application is a flexible food journal with information about calories, nutrients, and vitamins. But there can be lots of additional features on top of that.


Lifesum, Yazio, Lose It!, MyFitnessPal, and 8Fit are among the most popular apps for weight loss. Some of them are dedicated to one of the following features while others combine a few into one application:

  • A simple food journal
  • A database of foods, products, and restaurant items
  • A number of meal plans designed for specific purposes
  • A combination of meal plans and exercises
  • A community of dieters to share their stories
  • Access to communication channels with dietitians to get professional advice

The key is to have your own focus on some of these aspects and provide something unique. You should research the market and learn about the best nutrition apps in order to offer something new rather than following the well-trodden path.

Below, we highlight some of the factors that trouble the industry.

Simple Calorie Counting Doesn’t Work

Much media attention supporting the idea that food apps don’t work has been seen lately. While research proves thatfood journaling does workfor weight loss, the scrutiny is not unfounded. The basis of most weight-loss programs, including mobile apps, is calorie counting and consuming the right number of calories per day or per week. This scheme ignores many of the health aspects needed for sustainable weight loss such as resting metabolic rate, body fat percentage, and heart rate.

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While some apps add extensive information about various meals and their nutritional values, many don’t consider macronutrients and vitamins, which makes calorie counting less effective. Moreover, bodies have an individual reaction to certain foods and fitness activities so calorie consumption, as well as calorie burn, can’t be measured on a single universal table.

The issue of personalisation doesn’t have a perfect solution yet. But individualised measurements, generated by apps and wearables (or other useful devices like this one), are increasingly sophisticated, allowing for more accurate diet recommendations.

For many users, the most reliable way of losing weight or maintaining a healthy diet may require human interaction. For this reason, some health and nutrition apps give users access to online consultations with professionals in the paid versions.

Switching Between Diets Is Not That Easy

It’s amazing just how many diets are out there. With increased global communication, dieting plans and ideas are easily disseminated and popularised. Some diets, such as keto or Atkins, are popular enough to have applications dedicated solely to them. There are even companies making diet-specific apps. For example, Realized launched nearly thirty apps to guide people through a variety of meal plans from common ones like low-carb to more extreme ‘cabbage soup diet.’

What nutrition apps miss though is the opportunity to account for people who change their diets. It’s more or less a resolved issue in vegetarian and vegan apps – they suggest optimal alternatives to meals that a person ate before the transition. And food journaling apps allow users to change their eating habits and record them. But at the moment, no application is dedicated to helping users switch between diets healthily.

No Diet App Includes a Full, Global Selection of Foods and Meals

Applications that offer a database of items users can scan or manually search for are very convenient for swift food logging, especially if they include both separate products and prepared meals.

That said, it’s impossible to include every particular meal in the program. Including information from every single manufacturer or restaurant is a massive task, after all. But if mobile apps provide a barcode scanner, they need to include all the popular products in the target area, at least.

Workout Plans Are Also in the Game

Experts claim that exercising is an integral part of weight loss and workouts need to accompany meal plans. This is especially important when people reach their goals and then fail to consolidate their success, abandoning eating properly and exercising regularly. Again, healthy weight loss and maintenance has to be a permanent habit, not a one-time target.

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Since exercise is needed, people use two types of apps for weight loss: one for working out and the other for tracking their food intake. It’s apparent they would appreciate having both within a single program. Or they might also like two apps – one with workouts and one with meals – made by the same brand. Because this way, users won’t have any trouble synchronising their data between meal plans and fitness plans, which depend on each other to a great extent.

Integration with wearables is also crucial in the current climate. Released by the fitness tracker brand, Fitbit is massively popular because it combines fitness with nutrition. Freeletics is another example of a successful brand that caught the trend and made a nutrition guide app to accompany their workout app.

Nutrition and workouts are interconnected and the fact that users are looking for the best workout and diet plan app makes the competition even tougher – especially so when the fitness app market is competitive enough already.

People Are Looking for an All-in-One Diet Application

With that said, we can assume that people are looking for fewer solutions but more universal ones. You can go for a niche audience, limiting your users to a given region or a specific health condition but in any case, you have to make sure users don’t need to consult another app and that your program delivers every feature they expect.

Let’s take a look at the essential features of a weight-loss diet application.

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Essential Weight-Loss App Features

You can pick some of the features we describe as essential for any fitness app such as a thriving user community or game-like challenges. If you want to add workout plans to nutritional plans, check out our post on HIIT app development. For now, let’s get into the details of what to include in a diet app.

Personal Profiles

Since weight loss is about measuring health and body parameters, an application should feature a personal profile section. Users should be guided through the registration and onboarding procedure where they set their goals and preferences.

Keep in mind that privacy is a big issue for mobile users and you need to ensure the security of personal data. It cuts both ways: the more information from apps and trackers can be used in medical studies, the more accurate future healthcare solutions will be but users have to allow access to their data and know how it will be used.

Weight Tracking Log

We mentioned that the industry has been turning away from calculating calorie numbers and recording weight as a sole end goal. Nevertheless, weight tracking is essential for a diet app. There should be graphs to analyse progress and a daily log of measurements. It can be automatically integrated with frameworks like HealthKit. The core question is how the numbers are presented: it should be fun to add such data, and the app has to look positive in general. Progress can be represented in ways other than numbers: for example, the Snapshot feature in Cron-O-Meter allows users to compare and contrast photos of their body and estimates body fat percentages.

Diet Plans

Your app should provide meal plans based on weight goals and diet preferences. A useful addition would be an informative overview of different diets and how they can be applied to any particular case. All health dangers should be highlighted and personal details should be taken into account.

Diet plans have credibility if professional dietitians design them. It’s always good to have industry experts backing your product and supporting the idea of healthy weight loss. Don’t develop too many plans, as users can find it hard to navigate through all the offerings.

Dietitian Support

If you have professionals in the team, consider making a paid subscription that will include dietitian support. Studies show that people look for motivation before anything else in diet apps, and the ability to check in with professionals boosts both motivation and confidence. Among existing apps, Noom focuses the most on communication; each user becomes a member of a support group which is led by a coach.

Food Database

To free users from tiresome manual entries, include the following technologies into your app:

  • A barcode scanner – for identifying bought items
  • Visual recognition – for analysing a photo of a meal (for example, the Snap It feature in Lose It! identifies food values by a picture)
  • Autocomplete widgets – for suggesting known/recognised foods

Food databases should be flexible and smart: consider not only breaking products down into their nutritional components but also providing health ratings and suggesting alternatives to unhealthy ingredients. Fooducate is known for such functionality, it notifies users when harmful hidden ingredients are present. The gonutss app for vegetarians and vegans is good at smart suggestions too and gives tips for replacement products.

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Along with informing people about the nutrients they consume, a diet menu app can have a section with recipes suitable for each type of a diet plan. There are numerous ways to integrate recipes, beginning with simple text and ending with interactive videos.

Customisable recipes, so users can replace exotic ingredients with locally produced ones or swap out ingredients they are allergic to, is a feature that users will appreciate.

Goals and Rewards

People who struggle to lose or gain weight may need self-help interventions. They need someone, or even an impersonal something to cheer them up. Many app success stories show that nothing comes close to a reward system in terms of increasing motivation.

You can add a point system for each added meal or badges for reaching achievements on the path to a general goal. A social feed can help a lot here because people are likely to continue their fitness journey when they are involved in a community of like-minded individuals. Social support has been proven to boost results in weight-loss programs.

One app even adds financial motivation to the process. Pact gives cash rewards to members who reach their goals. These rewards are paid by members who missed their goals. Pact doesn’t have a food log so dieters have to use multiple programs, but the idea of supporting weight loss with money actually works.

Mood Journal

There are enough mood trackers as separate apps but this function can also be helpful in diet apps, especially those targeted at people with eating disorders. Most solutions for nutrition concentrate on food values, which is great, but they do miss the chance to ask people how they like certain meals. The best diet plan apps have an option to label foods or recipes as favourites and can encourage users to share more about how they felt about their meals. People that monitor both food intake and feelings are more likely to change their eating patterns.

Designing the Main Screen

Many fitness apps with similar purposes differ in what they present on the main screen. It could be a newsfeed or a log, it could feature some fun elements or accentuate a motivational message. You should design the main screen thoughtfully as this is what users will base their everyday impression on.

At MadAppGang we rebuilt our main screen several times while developing SmartRun to make sure it contains the core functions of the app and is attractive thanks to a simple animation.

If you have a fitness and nutrition app idea in mind, drop us a line. We’ll be happy to discuss how to implement your project and make a worthy mobile solution.

12 September 2019