LyteFast
Body Preview & Muscle Rating
Only for iPhone
Free · In-App Purchases · Designed for iPhone. Not verified for macOS.
iPhone
NEW: AI Body Preview shows the future you. Muscle Rating scores 8 muscle groups from a photo. Plus weight forecast, calorie tracking & AI food scan.
LyteFast is a weight-tracking app built to keep you moving—not just logging numbers. Now with AI Body Preview and AI Muscle Rating to make progress visible from day one.
NEW: AI Body Preview
See the future you. Pick a photo and the AI renders a realistic supermodel-physique preview of how you could look. Share the before/after to Instagram or TikTok.
NEW: AI Muscle Rating
Snap a photo and get an instant 1-100 score for each of 8 muscle groups (pectorals, shoulders, biceps, triceps, forearms, legs, abs, back), plus an overall rating and a gamified rank — Wood, Bronze, Silver, Gold, Platinum, Diamond, Champion, Titan, Olympian. See where you stand on the bell curve, get a comment per muscle, and share your card.
What also makes LyteFast different
Auto-Zoom chart that focuses on the most relevant slice of your journey, smooths daily noise, and projects a near-term weight forecast: Am I on track? When is the next milestone?
Budget-based calories (simple "spend vs. budget"):
- AI Food Scanner recognizes common foods and portions.
- Barcode Scanner pulls verified nutrition for packaged items.
- Instant budget status (on/near/over) plus remaining calories and friendly guidance.
Fasting, made actionable
Log fasting windows and see their measurable impact. An animated %-to-goal gauge shows where you stand. The Auto-Zoom prediction chart shows where you're headed. Grounded in research: benefits of time-restricted eating are largely mediated by total intake and consistency—LyteFast links fasting back to your budget, trend, and forecast.
Sustainability & sensitivities
Each meal scan includes estimated CO₂e (carbon footprint) so you can see environmental impact over days and weeks. Packaged items can display a gluten status indicator for quick screening. Insights inform—never judge.
Always know what to do next
A clear, always-visible calorie deficit view translates energy balance into plain language: how far you are from goal, what's driving the current trend (intake, activity, fasting), and the smallest effective changes to close the gap. On-budget notifications help you course-correct early.
Syncs when you do—works even if you don't
Fitness tracker & connected scale sync: steps, workouts, heart-rate-based estimates, and weigh-ins automatically. No tracker or smart scale? Manual weight entry. Choose from 60 activity types (from walking meetings to HIIT) to estimate calories burned—so your budget reflects your real day.
Fast logging without scanning
Use the Calorie Estimator with 60 predefined foods to compute intake quickly. Each item includes a simple carbon-footprint range (low / medium / high) and gluten status.
Evidence-based under the hood
Energy balance is the primary driver of weight change. Trend smoothing reduces day-to-day noise (hydration, sodium, timing). Short-horizon predictive modeling turns your recent trajectory into actionable forecasts. Self-monitoring + timely feedback supports adherence and long-term habits.
Why people stick with LyteFast
- Visual proof of progress: Body Preview lets you see the goal before you reach it.
- Gamified motivation: Muscle Rating turns your physique into a score worth chasing.
- Instant feedback after each scan.
- Fasting insights tied to outcomes—not hype.
- Eco & dietary signals at a glance.
- Activity-aware budgeting (sync or manual).
- Deficit clarity: always see the gap—and the best lever to close it.
Bottom line: LyteFast isn't just another calorie app. It's a motivation system built on proven principles. Open the app, scan or estimate a meal, see your body preview, check your muscle rating, and take the next step—with a forecast that shows exactly where those steps will lead.
All features are estimates for informational purposes and do not replace medical advice. AI Body Preview is a visualization, not a medical projection.
Ratings & Reviews
- This app has not received enough ratings or reviews to display an overview.
New in this version:
AI Body Preview
• Visualize the future you from a single photo
• Realistic supermodel-physique preview
• Share before/after to Instagram or TikTok
AI Muscle Rating
• Instant 1-100 score for 8 muscle groups (pectorals, shoulders, biceps, triceps, forearms, legs, abs, back)
• Gamified ranks from Wood to Olympian
• Bell-curve percentile and shareable card
Improvements
• Performance, stability, localization
Thank you for using LyteFast!
The developer, Stephane Sprauer, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Not Collected
The developer does not collect any data from this app.
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Size
- 63.6 MB
- Category
- Health & Fitness
- Compatibility
Requires iOS 18.0 or later.
- iPhone
Requires iOS 18.0 or later. - Mac
Requires macOS 15.0 or later and a Mac with Apple M1 chip or later. - Apple Vision
Requires visionOS 2.0 or later.
- iPhone
- Languages
English and 93 more
- English, Akan, Arabic, Aragonese, Asturian, Aymara, Basque, Belarusian, Breton, Catalan, Central Atlas Tamazight, Cornish, Corsican, Croatian, Czech, Danish, Dutch, Estonian, Ewe, Faeroese, Finnish, French, Frisian, Friulian, Fulah, Gaelic, Galician, Ganda, German, Greek, Guarani, Hawaiian, Hebrew, Hindi, Hungarian, Igbo, Indonesian, Irish, Italian, Japanese, Kabyle, Kashubian, Kinyarwanda, Korean, Ladin, Ladino, Latvian, Ligurian, Lithuanian, Lombard, Low German, Lower Sorbian, Lule Sami, Luxembourgish, Malay, Manx, Maori, Neapolitan, Northern Sami, Norwegian Bokmål, Norwegian Nynorsk, Occitan, Piemontese, Polish, Portuguese, Quechua, Rhaeto-Romance, Romanian, Russian, Rusyn, Samoan, Sardinian, Sicilian, Silesian, Simplified Chinese, Slovak, Southern Sami, Spanish, Swedish, Swiss German, Tachelhit, Tahitian, Thai, Tonga, Traditional Chinese, Turkish, Ukrainian, Upper Sorbian, Venetian, Vietnamese, Welsh, Wolof, Yiddish, Yoruba
- Age Rating
9+
- 9+
- Contains
Health or Wellness Topics
- In-App Purchases
Yes
- Weekly LyteFast AI Add-On 5,99 €
- Yearly LyteFast AI Add-On 179,99 €
- Yearly premium access 24,99 €
- Monthly premium access 2,99 €
- Monthly LyteFast AI Add-On 17,99 €
- Weekly premium access 0,99 €
- Provider
LyteFast
- LyteFast has identified itself as a trader for this app and confirmed that this product or service complies with European Union law.
- DUNS Number
284742344 - Address
60 RUE FRANCOIS IER
75008 PARIS
France - Phone Number
+33 613731993 - Email
stephane.sprauer@lytefast.com
- Copyright
- © 2026 LyteFast