Adverse events and tolerability of ketogenic diets - a systematic literature analysis.
Level 2 - randomized trial
Systematic review of prospective interventional studies
PubMed 41715236 · doi:10.1186/s40795-026-01277-5
What was done
A systematic review was conducted adhering to PRISMA guidelines using PubMed to evaluate prospective interventional studies published between 2019 and 2024 reporting adverse events from ketogenic diets. Adverse events were categorized using CTCAE criteria and analyzed across dietary variations, including classic ketogenic diet, modified Atkins diet, MCT-based ketogenic diet, and low glycemic index treatment (LGIT).
What was found
Across 36 studies with 42 ketogenic interventions, at least one adverse event occurred in 43% of participants (range 0–89%; 0.91 ± 0.71 adverse events per person). The most frequent categories were gastrointestinal (40%), neurological (17%), and metabolic/nutritional disorders (12%), with constipation being the most common specific complaint (24%). Stricter diets were linked to higher rates and severity of adverse events, with tolerability also influenced by age, underlying disease, and intervention duration.
Why it matters
This review characterizes the safety and tolerability profile of ketogenic diets across emerging clinical indications, showing that adverse events are common but largely gastrointestinal.
Limits
The total participant sample size was not reported in the abstract. The literature search was restricted to a single database (PubMed). The findings are limited by high heterogeneity in dietary regimens, lack of standardization, and variable documentation of adverse events.
Cited by
- supports Up to 40% to 50% of people experience gastrointestinal tolerability issues when consuming liquid MCT doses large enough to induce sustainable ketosis.