Background

Do diets given to mice model effects of similar diets eaten by humans?Obese humans have increased inflammation. High fat diets (HFD) produce obesity in most rodents, but almost no studies distinguish the effects of diet composition from effects of obesity on inflammation. Press releases about mouse HFD studies often claim relevance to human ketogenic diets even though HFD are not ketogenic and typically contain significant amounts of sucrose.

Methods

Scopus was used to identify the most cited papers with the keywords “mouse high fat diet”.440 papers were identified in PubMed with the search terms “mouse ketogenic diet”.Search of PubMed for the keyword “ketogenic diet” revealed 161 clinical trials with 72 randomized controlled trials (RCT).

Results

The five most cited mouse HFD papers all report that HFD induced obesity and increased various aspects of inflammation.Mouse ketogenic diet papers with matched ingredient control diets reported ketogenic levels of beta hydroxybutyrate and anti-inflammatory effects.Several clinical trials of ketogenic diets report effects on inflammation.One crossover double blind RCT of 3 high fat ketogenic diets consumed for 3 weeks each in 34 humans reported that ketogenic diets reduced the inflammatory marker C-reactive protein (CRP) levels.A one-year duration diet intervention study in 34 people compared people eating ad lib ketogenic diets to people eating calorie restricted moderate carbohydrate diets.Ketogenic diets decreased CRP levels and decreased body weight more than calorie restricted low fat diets.

Conclusions

Obese mice model obese human physiology.Ketogenic mouse diets model human ketogenic diets much more accurately than mouse high fat diets.At present there is no evidence that mouse HFD model the effects of ketogenic diets in humans for weight control or inflammation.Reviewers of papers and authors of press releases should require authors of mouse HFD papers to cite evidence of relevance to human high fat ketogenic diets.