One cannot completely apply laws of thermodynamics to the human body. We don't actually burn calories, as in catch fire. It's not just what we eat. It's what our bodies do with what we eat. And we have gut bacteria that also metabolize what we eat. We have hormones that direct our energy metabolism and appetite, and we also have emotional triggers and habits.
Hormones such as insulin, glucagon, leptin, and ghrelin. Carbohydrates cause the pancreas to produce insulin. If we didn't produce insulin, we would die from hyperglycemia and diabetic ketoacidosis (which is not the same thing as ketosis!). Our insulin drives the glucose into cells, where we use it for energy, or convert it to fat for energy storage in the liver, abdomen and subcutaneous regions. Our bodies can also use ketones (betahydroxybutyrate and acetoacetate for energy, and ketones) Our heart uses acetoacetate for preferentially over glucose. Insulin drives metabolism of glucose first if we ingest carbohydrates, as it is critical for us to avoid hyperglycemia.
If we produce less insulin through the ketogenic diet and/or intermittent fasting, we must utilize fatty acids for energy preferentially. Ketogenic diet can reverse Type 2 diabetes, reduce blood pressure, and rapidly reduce fatty liver disease. Indian and Asian populations have less obesity than those of African and European descent, but the rate of diabetes there is very high. Ketogenic diet has been a known treatment for epilepsy since the 1930s. It may have a role in mental disorders and cancer prevention, as well as an adjunct for cancer treatment. Insulin promotes tumor growh.
"Numerous epidemiological and pre-clinical studies have demonstrated that the insulin/insulin-like growth factor (IGF) system plays a key role in the development and progression of several types of cancer."
-Front. Endocrinol., 15 May 2015 |
https://doi.org/10.3389/fendo.2015.00077
The ketogenic diet was developed in the 1930s to treat intractible epilepsy in children. It induces many neurohormonal changes which can have many positive effects. This paper from 9 years ago in Epilepsy Research Journal discusses this rather succinctly.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3244537/