Effects of a Carbohydrate Meal on Lipolysis.

Background: Due to the increasing prevalence of obesity and type 2 diabetes, effective dietary recommendations are needed. Previously, we developed the low-insulin method: by avoiding insulinogenic, i.e., insulin-release-triggering foods, insulin secretion becomes reduced, lipolysis is stimulated, and energy production is shifted to ketosis with excess ketone bodies exhaled in the form of acetone. Now, we investigate how quickly stable ketosis (defined as fasting breath acetone concentration ≥ 7.0 ppm) is achieved, whether and for how long a carbohydrate meal inhibits ketosis, and whether the responses differ in healthy adults with different insulin levels.

Methods: An oral glucose tolerance test was conducted, and body composition and fasting insulin were determined at the beginning and end of the 14-day study. Participants ( = 10) followed a ketogenic diet and performed continuous glucose monitoring. Ketosis levels were determined by measuring breath acetone concentrations. On day 8, two white bread rolls with jam (72 g carbohydrates) were consumed for breakfast.

Results: After seven days, all participants achieved stable ketosis (defined as fasting breath acetone concentration ≥ 7.0 ppm), which dropped from 8.2 to 5.7 ppm ( = 0.0014) after the carbohydrate meal. It took five days to achieve stable ketosis again. The stratification of participants into tertiles according to their fasting insulin levels demonstrated that individuals with low fasting insulin levels achieved stable ketosis again after two days and those with medium insulin levels after five days, while those with high baseline values did not reach stable ketosis by the end of the study.

Conclusions: By carbohydrate restriction, stable ketosis can be achieved within one week. However, a single carbohydrate meal inhibits ketosis for several days. This effect is pronounced in individuals with elevated fasting insulin levels.