OneWay: Deficit

OneWay: Deficit — weight loss based on the first law of thermodynamics.

You run on calories the way a car runs on gas. A car stops when the tank is empty; your body keeps going by using stored energy. OneWay does not tell you what to eat or put you on a diet—it helps you log what you actually eat, learn how many calories are in it, and see whether you are in a surplus or deficit each day. Over time, that picture is what moves the scale.

Eat what you want. Build the habit of logging, notice patterns, and decide what to change based on real numbers—not rules from an app.

What OneWay does

• Log calories fast — breakfast, lunch, dinner, snacks.
• Import burn and weight from Apple Health — activity tracker + smart scale are required.
• Dashboard — surplus or deficit at a glance, day by day
• Stats — weight trends and cumulative deficit over time
• Smart Burn Calibration — after enough weigh-ins, OneWay suggests an adjustment so your burn estimate better matches your body (you choose whether to apply it)
• Smart Reminders — gentle nudges to log breakfast, lunch, and dinner
• Share Progress — share your journey with the details you choose — streaks, deficit, and weight progress

Hit your goals your way

OneWay does not set a target weight or calorie goal for you. You see the math—surplus, deficit, and trend—and use it to move toward your goals, with a healthcare or nutrition professional if you choose.

Best with

• Apple Health enabled (weight + active/resting energy)
• Activity tracker synced to Health for daily burn
• Smart scale syncing weight into Health
• Consistent logging and regular weigh-ins

Your data stays on your device

No accounts. No cloud sync. Calorie logs and settings are stored locally on your iPhone.

Educational tool — not medical advice

OneWay does not prescribe calorie targets, meal plans, or medical treatment. Work with a qualified professional before changing diet or exercise.

Pricing

OneWay is free to download. Core logging and HealthKit import are free. Smart Burn Calibration, Smart Reminders, Share Progress, and other Smart features require OneWay Smart — an optional auto-renewable subscription (monthly or yearly) with a free trial. Cancel anytime in App Store settings. No advertising.

Legal

Privacy Policy: https://onewaycoaching.app/privacy.html

Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/

OneWay Smart terms: https://onewaycoaching.app/terms.html