None of the coffee additives caused a significant drop in our blood ketone levels. At 120 minutes, my, (Becky’s), ketone readings increased after drinking black coffee, coffee with cream, coffee with MCT oil, and coffee with butter. At 120 minutes, Keith’s ketone readings dropped by 0.1 mmol/L after drinking only black coffee. His ketone readings rose slightly after consuming coffee with cream, MCT oil, and butter.
Because of the massive amount of sugar that Americans eat on average, most people have become dependent on glucose, instead of fatty acids, for energy. Every supermarket, grocery store and coffee shop sells an abundance of sugary foods and drinks. When you eat a lot of sugar, and that sugar isn't utilized for energy, your body breaks it down and eventually stores it as body fat.
The benefits of intermittent fasting translate to untrained overweight and obese individuals as well. One study published in Obesity Reviews found that eating fewer calories is effective for fat loss, but it does come with some muscle loss. However, if the subjects fasted for 24 hours and ate as much as they wanted on the next day for a period of 12 weeks, they lost significantly less muscle mass.

There are MUCH bigger fish to fry with regards to getting healthy than a few calories here and there during a fast. 80% adherence that you stick with for a year is better than 100% adherence that you abandon after a month because it was too restrictive. If you’re trying to get to a minimum bodyfat percentage, you’ll need to be more strict – until then, however, do what allows you to stay compliant!
There were [no statistical] differences between the low- and high- [meal frequency] groups for adiposity indices, appetite measurements or gut peptides (peptide YY and ghrelin) either before or after the intervention. We conclude that increasing meal frequency does not promote greater body weight loss under the conditions described in the present study.