This week

Fasting goal

You can also set this from the fire screen, including custom lengths.

Weight

Fasts

Cravings killed

Reminders

Ember nudges you when you hit your goal, and every six hours past a full day to check your electrolytes.

These work while Ember is open. Reminders that arrive with the app closed need the App Store version.

Appearance

In dark, the fire lights the whole interface as it grows.

Back up your data

Everything lives on this device only — nothing is sent anywhere. Clearing your browser data erases it, so keep a copy, especially before switching phones.

Electrolytes

Sodium, potassium and magnesium — why they matter on a fast, reference amounts, and simple recipes.

What holds up across the evidence

• Protein at every meal. It's the most satiating macronutrient and it protects lean mass while you lose weight — which is most of the reason people regain.
• Most of your food as things that were recently alive. Vegetables, fruit, meat, fish, eggs, legumes, dairy, whole grains.
• Fibre, deliberately. Most people eat roughly half of what's recommended, and it does much of the satiety work.
• Sodium, potassium, magnesium — especially on fasting days. A lot of "fasting feels terrible" is plain electrolyte loss.
• Resistance training two or three times a week. Fasting without it means a meaningful share of what you lose is muscle.

Ember deliberately doesn't set calorie or macro targets. Those are personal, and an app that doesn't know your history shouldn't hand them out.

What fasting actually does for weight

Head-to-head trials are fairly consistent: intermittent and extended fasting produce weight loss comparable to ordinary calorie restriction, not dramatically better. The advantage, where there is one, is adherence — some people find not eating easier than eating carefully.

That's a real advantage. It just isn't magic, and any app telling you otherwise is selling something.