Accepted answer
Start with what 1,100 kcal a day leaves you room for, because at that intake the deficit is a live competing explanation rather than a footnote. Protein is 4 kcal per gram, so 100 g costs 400 kcal — 36 per cent of the entire day's energy — and everything else has to come out of the remaining 700. A day that misses protein at 1,100 kcal has missed it by a wide margin, and nausea that tracks those days is a nutrition signal. Then separate the two by timing: a dose effect is periodic and phase-locked to the injection or to an increase, and a deficit effect is monotonic and gets worse the longer the intake stays at 1,100. Log intake, protein and nausea on the same daily row for a fortnight and the two patterns separate without any further cleverness. Nothing here is medical advice.
The honest answer is that this is usually fixable by eating more, which is unwelcome advice in this context.
Three days of honest weighed intake usually settles this. Estimated intake in this situation is systematically wrong and usually wrong in the direction that hides the problem.
Gastrointestinal adverse events, indicative pooled rates
| Event | Active arm | Placebo arm | Timing |
|---|
| Nausea | 40–45 % | 15–20 % | Peaks 1–2 wk after each step |
| Vomiting | 15–25 % | 5–8 % | Follows nausea |
| Diarrhoea | 20–30 % | 10–15 % | Early, variable |
| Constipation | 20–25 % | 8–12 % | Later onset, persistent |
| Discontinuation for GI events | 4–7 % | 1–2 % | Mostly during escalation |
Ranges span agents and doses; read the specific prescribing information for a specific figure.
Iron deficiency is common, particularly in menstruating women, and low intake plus a reduced red-meat share makes it more likely. Ferritin is the test, and it is an acute-phase reactant so it needs interpreting alongside CRP.
Self-reported intake underestimates measured intake by twenty per cent or more in doubly labelled water comparisons.
Nothing here is medical advice.
Sleep is a variable here too, and no amount of eating fixes sleep debt.
edited 7 Dec 2025 by sian_llewellyn — updated for the 2026 guidance change