Intermittent fasting apps got popular for one reason: a timer is easier to ship than a meal plan. But once you have used a fasting timer for two weeks, you discover the obvious thing nobody mentions in the App Store screenshots — the timer is not the workout. The food is.

The three windows worth tracking

16:8 is the default. Eight hours of eating, sixteen hours of fasting. Most people land here. 18:6 is a tighter version, common with people doing a short cut. OMAD — one meal a day — is the extreme end and works for a small subset who genuinely prefer it. There is no medal for the longer fast; there is only the one you can keep doing on a Tuesday.

What to log inside the window

Calories, protein, water. That is the short list. If you only track the timer, you can drift into a 1,200-calorie day or a 3,800-calorie day without noticing, and either one will sabotage whatever you were trying to achieve. The simplest setup is a fasting timer plus a calorie tracker that respects it — not a hard requirement, but it removes a layer of friction.

What to ignore

Autophagy charts, “fat burning zone” gauges, and any feature that promises a cellular benefit at hour 17. The science there is interesting and unfinished. The marketing is ahead of the science. Track behaviour, not biology.

Where AI helps

Photo logging is dramatically more useful when the eating window is short. You will not type out a chicken-and-rice bowl during a 45-minute lunch. You will take a photo. Pantry-aware meal planning matters even more on IF, because preparing one large meal is easier than improvising three small ones. Enerium handles both natively.

The honest summary

Intermittent fasting works for some people, fails for others, and is a tool — not a moral framework. Pick a window you can sustain, log the food inside it, and reassess after four weeks. If your weight, energy and training are moving in the right direction, keep going. If not, the problem is rarely the fast. It is the meal.