LyteFast: Weight Loss Tracker

Log your weight for free, sync your scale and fitness tracker, and see where you're heading. Core logging is free; the weight forecast, AI Muscle Rating, AI Body Preview and other premium features require a subscription (see below).

NEW: AI Body Preview (requires AI Add-On subscription)

Pick a photo and the AI generates a goal-physique visualization to help you imagine where your efforts could lead. Share the before/after to Instagram or TikTok. Results are AI-generated artistic renderings for motivational purposes only — not predictions, clinical assessments, or representations of your actual future appearance.

NEW: AI Muscle Rating (requires AI Add-On subscription)

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. Scores are AI-generated estimates, not clinical measurements.

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 (subscription required): Am I on track? When is the next milestone?

Budget-based calories — subscription required (simple "spend vs. budget"):
- AI Food Scanner recognizes common foods and portions (requires AI Add-On subscription).
- Barcode Scanner pulls verified nutrition for packaged items (requires AI Add-On subscription).
- Instant budget status (on/near/over) plus remaining calories and friendly guidance.

Fasting, made actionable (subscription required)

Log fasting windows and see their measurable impact. An animated %-to-goal gauge shows where you stand, and the Auto-Zoom chart shows where you're headed.

Sustainability & sensitivities (subscription required)

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 (subscription required)

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 & scale sync: steps, workouts, and weigh-ins automatically. No tracker? Manual entry. Choose from 60 activity types to estimate calories burned.

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.

What's free vs. subscription

Free: manual weight and step logging, calorie estimator, fitness tracker & scale sync, basic charts.
Base Access subscription: weight forecast, calorie deficit tracking, fasting log & insights, CO₂e footprint, gluten status indicator.
AI Add-On subscription: AI Food Scanner, Barcode Scanner, AI Body Preview, AI Muscle Rating.

Subscriptions are available as weekly, monthly, or yearly plans and are managed through your Apple ID. Payment is charged to your Apple ID account at confirmation of purchase. Subscriptions automatically renew unless cancelled at least 24 hours before the end of the current period. You can manage or cancel subscriptions in your Apple ID account settings at any time.

All features are estimates and do not replace medical, nutritional, or fitness advice. AI Body Preview generates artistic visualizations for motivational purposes only — not predictions and not representations of your actual future appearance. AI Muscle Rating scores are AI-generated estimates, not clinical measurements.