"Alternatively, fat overfeeding had minimal effects on fat...

"Alternatively, fat overfeeding had minimal effects on fat oxidation and total energy expenditure, leading to storage of 90-95% of excess energy. Excess dietary fat leads to greater fat accumulation than does excess dietary carbohydrate, and the difference was greatest early in the overfeeding period."

Fat and carbohydrate overfeeding in humans: different effects on energy storage
https://pubmed.ncbi.nlm.nih.gov/7598063/