Caps and alerts, not just goals

Set 150 g of protein, the bar fills, you feel good when it is full. The whole interface approaches a number from below.

Now try to use that interface to drink less soda. You can find “added sugar” in some apps and watch it climb. Nothing happens when it climbs past where you wanted it to stop — no line, no color change, no moment where the app says that one put you over. The bar keeps filling, indifferent, because the app has one idea and the idea is “more”.

AIM separates the two in the data model, not just the styling. A goal is approached from below and full is success — protein, fiber, vitamin C, water. A cap is a limit not to cross — sodium, added sugar, saturated fat, cholesterol, and anything you add yourself.

A capped metric behaves differently everywhere it appears: the bar fills toward the limit, passing it turns the bar a muted brick color rather than a celebratory one, and the day summary counts caps kept rather than bars filled. There is no confetti for staying under a limit, because staying under a limit is not an achievement, it is Tuesday.

Soda is the common case and it is not a nutrient. Neither is “takeaway meals” or “energy drinks”. Add it as a custom metric with a unit that means something to you:

Added sugar, grams, cap 25 g/day catches the soda and the cereal and the sauce. Sweetened drinks, count, cap 3/week catches the soda specifically, whatever the size. Alcohol units, cap 10/week works because a daily cap on that either forbids a normal Friday or is set so loosely it never fires.

The meal that crosses the line is flagged at the moment you log it — not in a digest at midnight when the information is useless — and the wording is plain. That takes you to 61 g of added sugar against a 25 g cap.

No emoji, no scolding, no suggestion that you have failed at something. You drew a line; the app's job is to tell you once, and then get out of the way.

People who cap added sugar are rarely surprised by the soda. Everyone knows about the soda. They are surprised by the pasta sauce, the granola, the flavored yogurt, the smoothie and the bread — the ones that eat a cap silently in a tracker that only counts up.