Weight Loss Without Willpower – an AI Coach That Adapts

01 /The Concept

Simple built a weight-loss app that delivers results without strict diets or medication.

The core of the app is an AI coach named Avo, which helps users adapt general weight-loss principles to their actual lives.

For example: walking into a restaurant or a grocery store, you can point your phone camera at the menu or the shelves – and the app will tell you which dishes to order or which products to buy to minimize their impact on your waistline.

More broadly, the AI coach builds a daily eating and activity plan around your existing habits and current progress – or backsliding – sending reminders along the way. Eat two servings of colorful fruits or vegetables at this time, take a thirty-minute walk at that time, and stay out of the fridge entirely after 9pm.

When you complete an action, you mark it in the app. When you don't, you don't. It also makes sense to log anything you eat beyond the coach's recommendations. With that data, Avo continuously refines its suggestions to match how you actually move and eat.

Based on what you do and don't do, the app tracks your progress and assigns it a score. The same reports make visible exactly which behaviors are helping you get closer to your goal and which are holding you back – and why. Over time, you can find a balance between the things you're not willing to give up and the results you actually want.

If you want broader guidance or want to talk through your current situation – weight, schedule, meal plan – you can have a natural-language conversation with Avo directly in the built-in chat.

A free tier covers basic features, which are enough to get started. The paid tier unlocks personalized advice, recommendations, and plans that help users achieve and sustain results faster. Pricing lands at around $15 per month depending on billing frequency.

The site claims the app is changing the lives of 17.5 million people. Based on available data, that's the total registered user count; monthly active users are in the range of 800,000.

Simple was founded in 2019. The app grew steadily until a pivotal moment in 2023: the launch of the Avo AI coach. In 2024, revenue grew 64% and hit $100M. The growth hasn't slowed – the most recent months put the app on a $160M annualized revenue run rate.

Those numbers caught investors' attention. Simple just raised $35M in new funding – though the founder says he didn't particularly need the capital but couldn't turn it down. For context: over the preceding years, the startup had raised only $10M in total.

02 /Why It Matters

Simple's central differentiator, in the founder's own words: "We work within your life, not against it."

As he puts it: "Most weight-loss apps are fixated on the end goal. We focus on the journey – adapting to users' real lives and habits. That's how you lose weight without extreme restrictions or the exhausting ritual of counting every calorie."

A recent study on 50,000 app users found that 42% had lost at least 5% of their body weight over the course of a year. People with strong willpower can certainly lose more, faster – but that requires restructuring life around the goal, which most people simply won't do.

Simple's approach is the inverse: fit achievable results around your existing comfort level. The app is essentially an answer to the question "how do I get at least some results without giving up the life I'm used to?" – which, it turns out, resonates with far more people than the maximalist approach. And not just when it comes to weight loss.

The potential market is enormous: more than 1 billion people worldwide are overweight, and a significant proportion would like to change that – ideally without extreme effort. The ideal weight-loss formula is simple: eat less, move more. The problem is that 1 billion people consistently can't follow it.

In the US, roughly 40% of the population is overweight. That figure is often attributed to the country's fast-food culture – but it's more complicated than that. Among countries with sufficient population and reasonably high income levels, Kuwait and Qatar rank first and second in obesity rates; the US is tied for third with Saudi Arabia. All countries in the top ten cluster in a similar range – between 34% and 45% of the adult population.

03 /Opportunities

This pattern holds across many areas of life: outstanding results are achievable if you're willing to reorganize your life around a goal. But very few people will make that sacrifice. The far more widely applicable principle is: "Help me get some results without asking me to leave my comfort zone"

Doing that requires the ability to calibrate achievable targets to each person's existing comfort level. AI makes this not just possible but relatively easy – constantly adapting the theoretical ideal to what's actually happening in real life.

That suggests a growing opportunity for AI apps built on this principle to help people achieve life goals of all kinds – and that's a broad territory for startup builders.

Apps like this are already emerging.

Sunflower ([related review](/review/na-nuzhno-menshe-pit-mozhno-ochen-neploho-zarabotat)) built an AI app for people struggling with alcohol or drug dependency. The addressable market there is also around 1 billion people worldwide. Just the day after the Sunflower review was published, the startup – currently in Y Combinator – announced nearly $4M in new funding, ahead of Demo Day, where it plans to raise more.

Sunnyside ([related review](/review/nado-menshe-pit)) targets drinkers as well, but with a concept that fits the comfort-zone principle even more precisely: it doesn't push anyone to quit entirely. It just helps people drink less to reduce the unpleasant and damaging effects of alcohol. Sunnyside has raised around $15M.

So – in what major life domain could you build an AI coach that helps people get at least some results without stepping outside their comfort zone?