Best 21 Days Metabolic Diet Apps

215+ iOS apps curated and reviewed

4.5 avg rating
18 free apps
Updated July 2026

Whether you're new to 21 days metabolic diet or looking for an upgrade, our curated collection of 215+ iOS apps has something for everyone. Each app is reviewed and rated by real users, helping you make an informed decision.

Compare top 21 Days Metabolic Diet Apps (July 2026)

#AppPriceRatingAdsIn-App PurchasesUpdated
121 Days Metabolic Diet21 Days Metabolic Diet$3.993.5★ (2)NoNoJul 2026
2Prime: Intermittent FastingPrime: Intermittent FastingFree4.6★ (4.6K)NoYesAug 2026
3Carbon - Macro Coach & TrackerCarbon - Macro Coach & TrackerFree4.8★ (7.9K)NoYesAug 2026
4FastEasy: Intermittent FastingFastEasy: Intermittent FastingFree4.6★ (79K)NoYesAug 2026
5Lumen - Metabolic CoachLumen - Metabolic CoachFree4.6★ (6.5K)NoNoAug 2026
6BodyFast: Intermittent FastingBodyFast: Intermittent FastingFree4.7★ (145K)NoYesAug 2026
7Stupid Simple Keto Diet AppStupid Simple Keto Diet AppFree4.6★ (8.9K)YesYesAug 2026
8no.Dietno.DietFree4.3★ (2.8K)NoYesAug 2026

Top Picks for 21 Days Metabolic Diet

Prime: Intermittent Fasting#2

Prime: Intermittent Fasting by Oksana Safronenko

The fasting app for women
Strong Contender
💪 Health & Fitness
4.6😐(4.6K ratings)
FreeIn-App Purchases
Prime: Intermittent Fasting screenshot 1
Prime: Intermittent Fasting screenshot 2
Prime: Intermittent Fasting screenshot 3
Prime: Intermittent Fasting screenshot 4
Prime: Intermittent Fasting screenshot 5
Prime: Intermittent Fasting screenshot 6

This app offers a tailored intermittent fasting experience for women, featuring a fasting tracker, weight monitoring, and personalized guidance. It helps users achieve fitness goals, manage weight, and understand the health benefits of fasting with a focus on women's specific needs.

What We Love

  • 👍 Easy to use
  • 🚀 Helpful for weight loss
  • 💡 Useful visual references
  • 👍 Responsive customer support

Room to Improve

  • 💰 Expensive subscription
  • 🐛 Buggy and laggy
  • 🔍 Lacking in-depth features
Carbon - Macro Coach & Tracker#3

Carbon - Macro Coach & Tracker by Reform LLC

Calories, Nutrition, & Diet
Worth Considering
💪 Health & Fitness
4.8😊(7.9K ratings)
FreeIn-App Purchases
Carbon - Macro Coach & Tracker screenshot 1
Carbon - Macro Coach & Tracker screenshot 2
Carbon - Macro Coach & Tracker screenshot 3
Carbon - Macro Coach & Tracker screenshot 4
Carbon - Macro Coach & Tracker screenshot 5
Carbon - Macro Coach & Tracker screenshot 6

This app provides personalized nutrition plans for weight loss, muscle gain, or maintenance. It adapts your plan as you progress and offers a comprehensive food tracker with a large database and barcode scanner. It supports various diet preferences and allows for custom meal planning.

What We Love

  • 🚀 Easy to use
  • 👍 Flexible and customizable
  • 🔍 Accurate food database
  • 💡 Helpful coaching and adjustments

Room to Improve

  • 🐛 Limited food database for some regions
  • 🤔 Strict adherence required for adjustments
  • 🤷‍♀️ Lack of exercise tracking integration

More 21 Days Metabolic Diet apps to explore

4
FastEasy: Intermittent Fasting
FastEasy: Intermittent Fasting
FastEasy: Intermittent Fasting
Simple Weight Loss & Tracker
Free

This app guides users through intermittent fasting to achieve weight loss and improve health. It offers customizable fasting plans, a timer, water tracking, and personalized recipes. Track your progress and gain insights into your body's changes.

Customizable fasting plansFasting timer and remindersWater intake tracker
💪 Health & Fitness
(79K)
free with in-app purchases
5
Lumen - Metabolic Coach
Lumen - Metabolic Coach
Lumen - Metabolic Coach
Hack your metabolism
Free

Gain control of your metabolism with real-time insights and personalized nutrition plans. This app helps you understand if your body is burning fats or carbs, offering guidance on what and when to eat for weight loss and a healthier lifestyle.

Real-time metabolic insightsPersonalized daily nutrition plansLifestyle recommendations
💪 Health & Fitness
(6.5K)
free with in-app purchases
6
BodyFast: Intermittent Fasting
BodyFast: Intermittent Fasting
BodyFast: Intermittent Fasting
Track Calories, Macros, Weight
Free

This app guides users through intermittent fasting to achieve weight loss, improve health, and boost energy. It offers personalized plans, daily coaching, recipes, and tools like a water tracker and weight log. Users can choose from various fasting plans and track their progress towards their health goals.

Personalized fasting plansDaily coaching and motivation100+ recipes for fasting success
💪 Health & Fitness
(145K)
free with in-app purchases
7
Stupid Simple Keto Diet App
Stupid Simple Keto Diet App
Stupid Simple Keto Diet App
Low Carb Diet & Macros Manager
Free

This app helps you track carbs and calories to achieve weight loss and maintain a ketogenic lifestyle. It offers easy food logging, progress tracking, and support for custom foods and fasting. Certified diet coaches are also available.

Visual carb and calorie loggingBarcode scanner for food entryFasting support
💪 Health & Fitness
(8.9K)
free with in-app purchases
8
no.Diet
no.Diet
no.Diet
Mediterranean Weight Loss Diet
Free

This app offers a personalized nutrition and lifestyle plan inspired by Mediterranean recipes to support weight loss, boost energy, and improve overall health. It focuses on building sustainable habits through meal tracking, mindful movement, and stress reduction techniques.

Personalized meal plansMediterranean recipe inspirationHabit tracking (meals, water, movement)
💪 Health & Fitness
(2.8K)
free with in-app purchases
9
My Challenge: Diet Plans
My Challenge: Diet Plans
My Challenge: Diet Plans
by KETO DIETS UAB
Free

This app offers a personalized low-carb diet plan designed by nutritionists and behavioral scientists. It provides meal planning with over 10,000 recipes, macronutrient tracking, progress monitoring, and expert guidance to help you achieve weight loss and improve overall health.

Personalized low-carb diet plans10,000+ carb-free recipesMacronutrient tracking
💪 Health & Fitness
(3.8K)
free with in-app purchases
10
Fooducate: Nutrition Coach
Fooducate: Nutrition Coach
Fooducate: Nutrition Coach
Calorie Counter & Diet Tracker
Free

This app helps millions track food intake, exercise, and sleep to improve health and achieve weight loss goals. It analyzes food quality, counts macros, and offers personalized dietary advice for various health needs. Scan barcodes to uncover hidden ingredients and discover healthier alternatives.

Log food intake and exerciseAnalyze calorie quality and macrosScan product barcodes for nutrition grades
💪 Health & Fitness
(78K)
free with in-app purchases
11
Fasting For Weight Loss App
Fasting For Weight Loss App
Fasting For Weight Loss App
Customized Fasting Plans
Free

This app helps you lose weight and improve health through customized intermittent fasting plans. It offers AI-powered food scanning, intelligent dietary advice, and progress tracking to support your goals without restrictive diets.

AI food scannerCustomized intermittent fasting plansNutrition and hydration tracking
💪 Health & Fitness
(6.3K)
free with in-app purchases
12
Formula - weight loss diet app
Formula - weight loss diet app
Formula - weight loss diet app
Anti-Inflammatory, Cortisol
Free

This app guides you through various specialized diets like Carnivore, Mediterranean, Anti-Inflammatory, and Cortisol Detox. It offers recipe libraries, meal tracking via voice or barcode, and expert support to help you achieve your health goals.

Automatic Nutrient CalculatorVoice and Barcode Meal LoggingExtensive Recipe Library
💪 Health & Fitness
(33K)
free with in-app purchases
13
DietBet: Lose Weight & Win!
DietBet: Lose Weight & Win!
DietBet: Lose Weight & Win!
Join over 1,000,000 players!
Free

Achieve your weight loss goals by joining supportive communities and participating in games hosted by experts. Make a pledge, track your progress, and win money when you reach your targets. This app helps build lasting healthy habits.

Weight loss goal settingCommunity supportExpert-hosted games
💪 Health & Fitness
(21K)
free with in-app purchases
14
Carnimeat
Carnimeat
Carnimeat
Carnivore Diet Meal Plan
Free

This app provides personalized meal plans and habit-building tools for a high-protein, carnivore lifestyle. It helps users burn fat, boost energy, improve digestion, and build sustainable eating habits with simple, meat-focused recipes and progress tracking.

Personalized meal plansHigh-protein carnivore recipesHabit building tools
💪 Health & Fitness
(2.6K)
free with in-app purchases
15
Unimeal: Fasting and Diet
Unimeal: Fasting and Diet
Unimeal: Fasting and Diet
Simple Weight Loss & Tracker
Free

Achieve your weight loss goals with personalized meal plans, intermittent fasting schedules, and easy-to-use calorie and weight tracking. Utilize an AI scanner for effortless food logging and access workouts and hydration reminders to support your journey.

Intermittent fasting customizationPersonalized meal plansAI food and nutrition scanner
💪 Health & Fitness
(13K)
free with in-app purchases
16
Fasting + Intermittent Fasting
Fasting + Intermittent Fasting
Fasting + Intermittent Fasting
Fasting Tracker - Lose Weight
Free

This app helps users achieve weight loss and improve metabolic health through intermittent fasting. It offers personalized plans, progress tracking, and coaching without dietary restrictions.

Advanced fasting and intermittent fasting trackerOver 15 free intermittent fasting plansCustomizable fasting plans
💪 Health & Fitness
(6.8K)
free with in-app purchases
17
Calorie Counter PRO MyNetDiary
Calorie Counter PRO MyNetDiary
Calorie Counter PRO MyNetDiary
Food Nutrition Fasting Tracker
$3.99

Easily track calories, food intake, and macronutrients with a powerful barcode scanner and AI meal logging. Offers personalized diet plans and detailed nutrition breakdowns to help users achieve their health goals.

Barcode scanner for fast loggingAI Meal Scan for instant food entryPersonalized diet and meal plans
💪 Health & Fitness
(14K)
freemium
18
WeightWatchers Program
WeightWatchers Program
WeightWatchers Program
Weight Loss and Better Health
Free

This app offers a science-backed weight loss tracker and personalized diet plans. It includes specialized support for weight-loss medications, AI-powered progress tracking beyond the scale, and flexible tools for various weight management goals. Connect with coaches and a supportive community for lasting results.

Personalized diet plansWeight-loss medication supportAI body scanner
💪 Health & Fitness
(2.4M)
free with in-app purchases
19
The Fast Metabolism Diet
The Fast Metabolism Diet
The Fast Metabolism Diet
by Brainstorming Session Inc.
Free

This app supports a 28-day diet plan focused on metabolism boosting without calorie counting. It provides comprehensive food lists, customizable meal planning, and progress tracking tools to help users adhere to the diet's phases and achieve weight loss goals.

Customizable menu planningComprehensive food lists by phaseOver 250 selectable meals
💪 Health & Fitness
(186)
free
20
Perfect Body - Meal planner
Perfect Body - Meal planner
Perfect Body - Meal planner
Your meal & workout planner
Free

This app offers personalized meal plans and adaptive home workouts to support weight loss and wellness goals. It includes daily challenges, progress tracking, and over 1,000 healthy recipes to help build sustainable, positive habits for a healthier lifestyle.

Personalized meal plansAdaptive home workoutsOver 1,000 healthy recipes
💪 Health & Fitness
(6.9K)
subscription

FAQ about 21 Days Metabolic Diet

What are the best 21 days metabolic diet apps for iPhone?
21 Days Metabolic Diet tops our 21 days metabolic diet apps ranking as of July 2026, with a 3.5-star average from 2 App Store ratings, and it's priced at $3.99.
Yes — 18 of the top 21 days metabolic diet apps we rank are free to download, including Prime: Intermittent Fasting and Carbon - Macro Coach & Tracker.
21 Days Metabolic Diet has no ads and has no in-app purchases, according to its App Store listing as of July 2026.
We track 215+ 21 days metabolic diet apps on the iOS App Store as of July 2026, ranked by rating, recency, and analysis of real user reviews.
The 21 Days Metabolic Diet app is a guideline designed to accompany users through a 21-day metabolic diet. It provides meal suggestions, recipes, supplement instructions, and tools to track weight loss progress.
The 21 Days Metabolic Diet app is a paid application, available for $3.99. This one-time purchase grants access to all its features.