SlimFast for the AI era? Weight loss app Simple raises $35M from Kevin Hart’s fund

Kevin Hart’s venture capital firm, Hartbeat Ventures, has led a $35 million Series B funding round for Simple, a London-based AI-powered weight loss app that uses behavioral coaching instead of calorie counting. The investment positions Hart’s firm to capitalize on the growing AI wellness market, while Simple aims to use the capital for hyper-personalization features and gamified experiences that have shown promising early results in user retention and weight loss success.

What you should know: Simple takes a behavior-first approach to weight loss, ditching traditional calorie counting for AI-driven habit coaching through its virtual guide, Avo.

• The app adapts to user inputs like food logs, hydration, and activity to provide personalized intermittent fasting schedules, targeted reminders, and real-time nutrition feedback.
• A free version offers basic tools including Nutrition Scores and wellness trackers, while paid subscribers ($17.99 monthly) get daily check-ins and access to an educational library.
• Liquidity, an AI-driven private credit firm, also participated in the funding round.

The big picture: Simple has achieved significant financial milestones that set the stage for expansion into more sophisticated AI features.

• The company generated $100 million in revenue in 2024 with 64% year-over-year growth while maintaining operating profitability.
• Avo delivered 19 million coaching messages in January 2025 alone, demonstrating substantial user engagement.
• A peer-reviewed study of over 50,000 users found that 42% achieved at least 5% weight loss after one year, with higher engagement linked to better outcomes.

Where the money goes: The new capital will fund advanced personalization and gamification initiatives designed to improve user experience and outcomes.

• Simple plans to develop hyper-personalization features that adapt in real time to user behavior and preferences.
• The company is building more intelligent coaching capabilities to provide human-like support through AI.
• A gamified companion experience currently in development has shown increased retention and weight-loss success in early testing and is expected to launch later this year.

What they’re saying: Leadership emphasizes the journey-focused approach over traditional goal-oriented weight loss methods.

• “Most weight-loss solutions fixate on the end goal,” said Mike Prytkov, founder and CEO of Simple. “We focus on the journey, making it adaptive, rewarding and sustainable. With our data and approach, there’s no need for obsessive calorie counting or extreme restrictions.”
• “I’m hyped to back Simple through my fund Hartbeat Ventures,” Hart said. “Simple is truly changing the game in health, and HBV wants to be front row for that.”

The broader context: While AI fitness apps show promise, industry experts raise concerns about potential negative behavioral impacts.

• A recent Levity survey found that 46% of fitness professionals have observed unhealthy or obsessive behaviors linked to AI-driven tracking apps.
• Trainers warn that overreliance on digital tools can lead to anxiety, disordered habits, and misinformation.
• Simple’s education-focused, moderation-based approach may offer a healthier alternative to more intensive tracking methods.

Strategic positioning: The investment adds Simple to Hartbeat Ventures’ growing portfolio of health and wellness companies, including VitaHustle, Function Health, SweatPals, and Palta.