The numbers
This is arithmetic, not medicine. It takes the calories already in the refrigerator, estimates what a body of a given size burns, and shows the difference over time. The direction is trustworthy; the decimal place is not.
Whose plan
The calorie figure comes off this week's schedule.
1281 cal a day, averaged across 7 days
You
Used by the equation
How much you move
Baseline
Training on top
How long
What that comes to
Resting burn
1,647cal
Daily burn
2,384cal
Deficit
1,103cal/day
After 12 weeks
156.4lb
Change
−24.6lb
To 165 lb
8weeks
The line bends because resting burn falls as you get lighter, so the same food becomes a smaller deficit. A straight line would flatter the plan. Training is priced separately at about 119 cal a day, averaged across the week.
This plan feeds you 366 calories a day below your resting requirement — the energy your body uses lying still. A deficit that size sustained for months is worth running past a doctor rather than a website.
A deficit above 1,000 calories a day is aggressive. It works, and it is also where people lose muscle alongside fat unless protein and resistance training hold it in place.
Apple Health
There is no way for a website to ask Apple Health for your data. It lives on the phone, and Apple publishes no server API for it — the only routes are an iPhone app holding a HealthKit entitlement, or the export the Health app makes on request. ChatGPT Health can read Apple Health, but it reads it into ChatGPT and offers nothing for a page like this one to connect to. So this takes the export.
On your iPhone: Health → your picture, top right → Export All Health Data. That produces export.zip. Hand it over below. It is unzipped and read inside this browser tab and never uploaded — this site has no server to upload it to.