Cardiometabolic function isn't the same as metabolic syndrome. Cardiometabolic function would be like a spectrum or perhaps a map. Metabolic syndrome would be the section of spectrum(say red in the rainbow) or area on the map (like a swamp) that designates the "danger zone."

Here the term "optimal" is used and that's around 7 percent as having optimal cardiometabolic function. That doesn't instantly mean 93 percent are impaired. The other classes are **intermediate, which is half of people, ** and lastly poor which was ~44 percent.

https://www.nature.com/articles/s41568-021-00388-4

https://link.springer.com/article/10.1186/s40170-020-00237-2

Fat can be oxidized for ATP via β-oxidation (look up FAO or catabolism, or see above links.) Fat → fatty acids → β-oxidation → acetyl-CoA + electron carriers → electron transport chain → ATP.

Example: Palmitic acid, a 16-carbon fatty acid, undergoes 7 rounds of β-oxidation producing 8 acetyl-CoA total. After everything runs through the Krebs cycle and electron transport chain, you end up with roughly 106 ATP. Which is a huge amount compared with glucose(1 glucose is about 30 ATP.)