A couple of years ago, I posted a piece about my adoption of a variation of an Intermittent Fasting diet, with a promise to follow up on how it went long term. Two and three-quarter years in, I think I am ready to draw conclusions, so here we are.
I was introduced to the idea by a BBC Horizon documentary, that, amongst other related topics showed how it had been discovered that humans metabolise and respond to protein intake on a 48 hour cycle, with potentially harmful low or high levels of some hormones arising from keeping the body stuck in the first stage by daily protein feasts. The same programme also looked at the more inconclusive effects of Caloric Restriction, which was not a novel concept to me, but which I viewed with some scepticism. However, the section on protein metabolism was so clear, that I could no longer eat daily meat, knowing what I learned that evening.
After a day or two of consideration and comparison of the various IF strategies, particularly Alternate Day and 5:2, I settled on a usual regime of 4:3, having a low calorie vegetarian diet on Mondays, Wednesdays and Fridays, although not as extremely low as 5:2 and CR followers go, and eating more indulgently on Tuesdays, Thursdays, weekends and holidays. This, on the one hand, puts me in the vital second stage of the protein cycle three times a week, but on the other hand, never leaves me more than a day away from a good meal, which is psychologically easy to cope with.
In the early weeks, I lost over a stone, and from the greatly increased ease in bending, I think much of the loss was the internal abdominal fat that no doctor ever has a good word for. However, after about a year, my overall weight started to creep back towards its original level, which I presume is my natural equilibrium. Although the weight has now come back, it does not feel as if it has returned as undesirable internal fat. Another effect has been that when I return to eating daily full meals on holiday, my body now furiously lays down reserves, and my weight temporarily soars, before falling back over a few weeks of resumed 4:3.
Initially, I was rather troubled by hunger on my low-cal days, but I have found that in the long term my appetite has adjusted, and I no longer miss proper meals on the days I don't eat them, and need just a few snacks to remain satisfied from the previous day's food until evening, even if I sometimes need a little supper.
I have seen it suggested that these kinds of restricted or partially restricted diets can be beneficial to immune system problems, such as allergies. I have no idea whether the continuing disappearance of my asthma since the time I started 4:3 IF is causally linked, or mere random co-incidence. It seems prudent to act on the assumption that it is causal, though, which is as powerful an incentive as any to carry on.
About a year into the diet, I had an opportunity to get a general blood test. My previous one had showed excessive cholesterol, and I was interested to see if my changed eating habits had helped to reduce it. I was pleased to see that, while my cholesterol level was still undesirably high, it had fallen out of the danger zone. That is still something that I need to keep watch over, but the first result was encouraging.
My long-term conclusion, therefore, is that 4:3 IF is delivering a healthier life for me, at no more downside than sometimes feeling a bit peckish. I would recommend it to anyone interested in maximising their own health, unless they already have ailments that are aggravated by an uneven food intake.