Accepted answer
Start with what 900 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 — 44 per cent of the entire day's energy — and everything else has to come out of the remaining 500. A day that misses protein at 900 kcal has missed it by a wide margin, and headache 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 900. Log intake, protein and headache 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.
Carbohydrate intake specifically affects training performance and perceived energy at a given total intake, which is why very low carbohydrate approaches feel worse in the gym at matched energy.
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.
Concretely, sleep quality often changes during rapid weight loss in both directions, and sleep debt produces fatigue that no amount of dietary adjustment will fix.
Self-reported intake underestimates measured intake by twenty per cent or more in doubly labelled water comparisons.
Nothing here is medical advice.
If it persists at an adequate intake, get bloods rather than more theories.
3Same experience here, different supplier. – rune_thoresen 2 months ago add a comment