The FastDay Forum

Most of the benefits of fasting come from the lack of carbohydrate intake, particularly the generation of ketones, so any combination of fasting and low carb would be likely to be beneficial.

I have written a bit about this in the fasting section of the site: https://www.fastday.com/fasting/how-can ... of-cancer/

Cancer cells burn a lot of glucose, so the theory of some enthusiasts is that a ketogenic diet denies that glucose to cancer cells, slowing their growth. But this would only benefit people who are running high blood sugars, as the body will maintain a normal blood sugar whether or not you eat dietary carbs.

The flaw in this reasoning is that to meet the demands of voracious cancer cells, if carbs aren't coming from food, the liver converts muscle to glucose, hence the swift wasting characteristic of cancer.

I have seen zero compelling evidence in published research that keto diets prevent or retard cancer, sadly. OTOH, the healing effect of a stringent keto diet on refractory juvenile epilepsy is very well documented. I'm very glad it is helping your son.

However, the epilepsy keto diet is far more extreme than the weight loss versions, and should not be done without instructions from a dietitian who works with neurologists.

The one well documented case of a death attributed to a keto diet was in someone who did not read the popular diet books but made up their own very low calorie keto diet. It was the electrolyte imbalance that did them in, if I recall correctly. Keto diets flush out a lot of them. But any sustained very low cal diet, i.e. 500 or 600 cals a day will do that too.

Another reason I doubt the usefulness of keto diets on cancer is that several of the people most visible in the online low carb communities back in the 1990s have died young of cancer, including the founder of Low Carb Friends.

Getting back to the topic at hand, no more than 2 days is very wise. Getting obsessed with fasting in a classic sign a person is developing a serious eating disorder. I'm not even entirely sure alternate day fasting is a good idea for that reason, to say nothing of the potential for slowing metabolism. Slow and steady with weight loss between 1 and .5 lbs a week is much more reasonable.