3 claims that cleared review. Each one shows what has to be true for it to hold and how strongly it is supported — including the places the sources contradict each other.
The glucose rise after a meal is a cardiovascular risk variable in its own right, predicting atherosclerosis and cardiovascular events independently of fasting glucose, so lowering post-meal glucose is a cardiovascular intervention and not only a glycaemic one.
How high your blood sugar climbs after eating matters for your heart, not just for diabetes. It can be a problem even when your fasting blood sugar reads normal.
Only when
holds in people whose fasting glucose is in the normal range, not only in diagnosed diabetes
the proposed mechanism is reduced demand on pancreatic beta cells and reduced glycaemic excursion, not a demonstrated causal chain to events
Who
general adults, including those with normal fasting glucose, and adults with type 2 diabetes
Moderate confidence
Three independent first authors, all peer-reviewed papers, but the strongest evidence is observational and mechanistic; no trial in this cluster shows that lowering post-meal glucose lowers events.
3 independent people · 3 sources · strongest evidence: observational
Sources
Whey protein consumption following fasted exercise reduces early postprandial glycaemia in centrally obese males: a randomised controlled trial. · European journal of nutrition · 2021 · doi:10.1007/s00394-020-02304-2
Longitudinal Associations of Dietary Sugars and Glycaemic Index with Indices of Glucose Metabolism and Body Fatness during 3-Year Weight Loss Maintenance: A PREVIEW Sub-Study. · Nutrients · 2023 · doi:10.3390/nu15092083
Efficacy of Postprandial Exercise in Mitigating Glycemic Responses in Overweight Individuals and Individuals with Obesity and Type 2 Diabetes-A Systematic Review and Meta-Analysis. · Nutrients · 2023 · doi:10.3390/nu15204489
Where body fat sits matters more than how much there is: visceral and android fat are positively associated with cardiovascular and type 2 diabetes risk factors, while abdominal subcutaneous, gynoid and leg fat are neutral or protective, more so in women.
Fat around the organs and midsection raises heart and diabetes risk; fat on hips and legs does not, and may even protect. Measure your waist, not only your weight.
Only when
the protective association for lower-body and subcutaneous fat is stronger in women than in men
excess visceral fat specifically tracks with high blood pressure, impaired fasting glucose, type 2 diabetes, metabolic syndrome and low-grade chronic inflammation
observational associations across general adult populations, not intervention evidence
Who
general adults; protective associations stronger in women
Moderate confidence
Two independent voices across two journal sources agreeing on a well-established association, with the strongest ladder tier being observational (dehghan-a); paoli-antonio's contribution is narrative-review background. Not raised to high because neither member is an intervention or a meta-analysis and one is a large prior study restated by its own authors. Both members state the same proposition, so nothing was excluded despite the lowered threshold.
2 independent people · 2 sources · strongest evidence: observational
Sources
A prospective study of the relationships between change in body composition and cardiovascular risk factors across the menopause. · Menopause (New York, N.Y.) · 2021 · doi:10.1097/GME.0000000000001721
Effects of 30 days of ketogenic diet on body composition, muscle strength, muscle area, metabolism, and performance in semi-professional soccer players. · Journal of the International Society of Sports Nutrition · 2021 · doi:10.1186/s12970-021-00459-9
A recent history of stroke or myocardial infarction is currently treated as an absolute contraindication to starting a ketogenic diet -- not because harm has been demonstrated, but because current safety evidence in this population is preclinical only, so a ketogenic diet should not be recommended even if other coexisting conditions might otherwise favor it.
If someone has recently had a stroke or heart attack, a ketogenic diet should be avoided for now. This isn't because it's been proven harmful -- it just hasn't been tested safely in people with this history yet.
Safety. Harmful if misapplied. The conditions above are not optional detail.
Only when
current evidence is insufficient to either confirm or refute the ketogenic diet's safety in people with a recent stroke or myocardial infarction -- the contraindication is precautionary, not based on demonstrated harm
supportive evidence for potential benefit in this population is currently preclinical only (not tested in humans with this history)
the contraindication holds even when another coexisting condition (e.g. obesity, type 2 diabetes) might otherwise make a ketogenic diet an attractive option
Who
adults with a recent history of stroke or myocardial infarction
Moderate confidence
All three members are from a single dedicated review on ketogenic-diet contraindications (watanabe-m); the strongest evidence tier present is mechanistic reasoning about absent human safety data, not primary trial or observational evidence, but the claim itself restates an established, precautionary clinical practice position (absolute contraindication) rather than a novel data-driven finding, so moderate confidence reflects that this is current clinical consensus without independent corroboration in this corpus.
1 independent person · 1 source · strongest evidence: mechanistic
Sources
Scientific evidence underlying contraindications to the ketogenic diet: An update. · Obesity reviews : an official journal of the International Association for the Study of Obesity · 2020 · doi:10.1111/obr.13053
This is a summary of published research, not medical advice. It cannot account for your medications, conditions or history. Talk to a clinician before acting on any of it.