Metabolic & Cardiometabolic
postprandial glucose spikes causes fatigue in healthy people
In plain terms: Do sugar spikes make healthy people tired and crash-y?
Part of: • postprandial glucose spikes
Partly — the post-spike glucose dip does track with hunger and a short-lived rise in fatigue, but "chronic fatigue from spikes" in healthy people is not established.
Evidence ladder
How far up the ladder this claim has climbed. A high consensus on a low rung means "consistent so far," not "proven in people."
Top evidence so far: Population patterns (Observational)
How the studies fall
The evidence (3)
| Source | Grade | Stance | Quality | Finding |
|---|---|---|---|---|
| Mantantzis 2019 · Neurosci Biobehav Rev | meta-analysis | mixed | high | Meta-analysis of 31 studies/1,259 mostly healthy participants: carbohydrate raised fatigue and lowered alertness within the first hour — supports a transient post-carb fatigue, but this tracks the carb load itself, not a distinct spike-then-crash, and debunks the sugar rush. |
| Kosuda 2022 · J Nippon Med Sch | observational | mixed | low | Symptomatic post-meal weakness/hunger (idiopathic postprandial syndrome) is described in non-diabetics but linked to abnormal glucagon response in a symptomatic subgroup, not to ordinary spikes in the general healthy population. |
| Wyatt 2021 · Nat Metab | observational | supports | high | In 1,070 healthy adults on CGM, larger 2-3h glucose dips predicted more hunger, sooner next meal and higher energy intake — but the outcome is appetite, not fatigue/energy-crash per se, and it is correlational. |
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