These diets can sometimes cause dangerously low blood sugar or dangerous acid buildup in the blood, so they should be done with a doctor’s guidance.
Scientific Claim
In overweight or obese adults, ketogenic diet and intermittent fasting may be associated with health risks such as hypoglycemia and ketoacidosis, indicating the need for medical supervision during implementation.
Original Statement
“The study also found that ketogenic diet and intermittent fasting have their own advantages in reducing body fat rate, but they may also bring certain health risks, such as hypoglycemia and ketoacidosis. Therefore, doctors or nutritionists should tailor the diet plan according to individual conditions and pay attention to its potential side effects.”
Evidence Quality Assessment
Claim Status
appropriately stated
Study Design Support
Design supports claim
Appropriate Language Strength
association
Can only show association/correlation
Assessment Explanation
The authors use cautious language ('may also bring certain health risks') and recommend supervision, which appropriately reflects the observational nature of adverse event reporting in this RCT without quantifying incidence.
Gold Standard Evidence Needed
According to GRADE and EBM methodology, here is what ideal scientific evidence would look like to definitively prove or disprove this specific claim, ordered from strongest to weakest evidence.
Prospective Cohort StudyLevel 2bIncidence rate of hypoglycemia and ketoacidosis in overweight/obese adults following ketogenic diet or intermittent fasting over time.
Incidence rate of hypoglycemia and ketoacidosis in overweight/obese adults following ketogenic diet or intermittent fasting over time.
What This Would Prove
Incidence rate of hypoglycemia and ketoacidosis in overweight/obese adults following ketogenic diet or intermittent fasting over time.
Ideal Study Design
A 1-year prospective cohort of 1000 overweight/obese adults initiating ketogenic diet or 5:2 fasting, with monthly monitoring of blood glucose, ketones, and clinical symptoms, and adjudicated diagnosis of hypoglycemia/ketoacidosis by physicians.
Limitation: Cannot establish causation if events occur in individuals with pre-existing conditions.
Randomized Controlled TrialLevel 1bCausal risk of ketoacidosis or hypoglycemia from ketogenic diet or intermittent fasting compared to control diets.
Causal risk of ketoacidosis or hypoglycemia from ketogenic diet or intermittent fasting compared to control diets.
What This Would Prove
Causal risk of ketoacidosis or hypoglycemia from ketogenic diet or intermittent fasting compared to control diets.
Ideal Study Design
A multicenter RCT of 500 adults with obesity and no diabetes, randomized to keto diet, IF, or control, with daily glucose monitoring, ketone testing, and mandatory reporting of adverse events over 12 weeks.
Limitation: Ethical constraints limit exposure to high-risk populations (e.g., type 1 diabetics).
Case-Control StudyLevel 3bWhether individuals who develop ketoacidosis while on these diets had higher risk factors than controls.
Whether individuals who develop ketoacidosis while on these diets had higher risk factors than controls.
What This Would Prove
Whether individuals who develop ketoacidosis while on these diets had higher risk factors than controls.
Ideal Study Design
A case-control study comparing 50 adults hospitalized for ketoacidosis while on keto/IF to 150 matched controls on same diets without events, assessing prior diabetes, medication use, and dietary adherence.
Limitation: Retrospective design prone to recall and selection bias.
Evidence from Studies
Supporting (1)
Study on the influence of ketogenic diet and intermittent fasting on the change of body fat rate
This study found that eating very low-carb and skipping meals sometimes can help overweight people lose weight, but it can also make some people feel sick or have dangerous blood sugar problems — so they should check with a doctor first.