Thankfully, coffee has zero calories. (Photo by Erik)
Time for another update on my intermittent fasting experiment, which has been running for 10 months now. As you probably know, intermittent fasting means alternating periods of eating with periods of fasting. The length of these periods varies depending on the type of intermittent fasting one does.
So far, I've been doing the 24/24 hour cycle, meaning that I eat for 24 hours and then fast for 24 hours. This is known also as alternate-day fasting (ADF) or every other day fasting (EOD). It has worked very well for me: the fasting periods are short enough for the hunger to be very bearable but long enough to (hopefully) see some long-term benefits such as improved insulin sensitivity and reduced mitochondrial damage. If you want to read more about what intermittent fasting is like in practice, I've written blog posts on my typical day and my typical high-fat, low-carb meal.
Starting yesterday, I've switched my eating schedule a little and experimented with another version of intermittent fasting, known as the condensed eating window. Essentially, this just means eating only during certain hours of the day. The difference to the 24/24 hour cycle is that the eating period does not continue onto the next day. A popularized version of this is the Fast-5 Diet, which promotes an eating window of 5 hours.
The way I do it is that I fast during morning and day and then break the fast when I get home from work. If I stop eating at midnight, this results in daily fasts of 16-18 hours and eating windows of 6-8 hours. So no breakfast and lunch but a big dinner and evening snacks.
There are various claims as to whether this kind of diet is healthy. One study suggested that eating only one big meal instead of the usual three may result in poorer insulin sensitivity and glucose tolerance and slightly higher blood pressure. On the other hand, body weight and stress hormone levels were reduced.
As discussed in the links above, the methodology of the study seems somewhat suspect. In any case, I won't be eating just one huge meal, but spread my energy intake throughout the 6 to 8 hours. For weight loss purposes eating only once per day may work, but I'm attempting to maintain my weight.
For more information on diets and health, see these posts:
Intermittent Fasting: Understanding the Hunger Cycle
Low-Carb vs. Low-Fat: Effects on Weight Loss and Cholesterol in Overweight Men
The Effects of a High-Fat Diet on Health and Weight: Does It Raise Cholesterol?
How Does Fructose Affect Triglyceride and Cholesterol Levels?