Updated: Jul 6
I would never recommend anything for you that I haven't tried myself.
You always ask about intermittent fasting. So, after seeking the expertise of a friend who started IF'ing before it was cool, I tried intermittent fasting. I did it for about 6 weeks. This seemed to be a decent period of time to reap some of the benefits touted by its proponents.
I also wrote a paper on it for my Advanced Biochem class. And today, I'm going to share it with you. Haha. I am making you read an essay this week. You're welcome.
When I copied my paper, I lost the source links. They are listed at the bottom of the paper.
In youth, one rarely considers the implications of aging. As one gets older, however, the realities of aging are hard to ignore. Bodies hurt, brains deteriorate, diseases are acquired, and energy is lost.
Does it have to be this way? Are there cultural practices that Westerners engage in that accelerate aging? Or is aging dependent more on the environment around us? Both the mitochondrial and the metabolic theories of aging posit that waste products in the body contribute to the aging process. The research is clear that prolonged and steady caloric restriction both slows down the metabolism (source) and also “results in long-term changes in appetite gut hormones, postulated to favor increased appetite and weight regain”(source). However, the metabolic theory of aging states that caloric restriction slows the aging process. I believe that time-restricted feeding can have similar anti-aging benefits as calorie-restricted feeding.
Proponents of calorie-restricted feeding tout the benefits of this intervention: mitochondrial activity is modulated and oxidative damage is decreased (source). As stated by Lopez-Lluch, “calorie restriction (CR) is “to date, the most successful intervention to delay aging progression or the development of age‐related chronic diseases” (source). Aging can be quantifiably measured by looking at the impairment of mitochondria, the increase in reactive oxygen species generation, and a decrease in antioxidant defense, leading to oxidative damage (source). Reactive oxygen species are at the root of mutated DNA that is associated with premature aging (source). Any time humans eat anything, even healthy and wholesome food, some degree of free radical activity occurs in the body. With calorie restriction, it is possible to eat 3, 4, 5 oven six times a day. And in fact, with a calorie restricted diet (1200 calories a day for women and 1400 calories a day for men, or about a 30% restriction [source]), it may be necessary to eat more often throughout the day in order to ward off hunger experienced by eating a low calorie diet.
The research is there- calorie restriction promotes longevity and health. However, have you every tried to eat 1200 calories a day for an extended period of time? I have. It’s near impossible. It’s hard on the body and hard on the mind. The spirit is willing, as it were, but the flesh is weak. In fact, the effects of prolonged calorie restriction on healthy volunteers was studied by Dr. Ancel Keys in his Minnesota Starvation Experiment. Not only did his volunteers’ metabolic rate drop by 40% in six months, they also experienced a low basal body temperature, brittle skin and nails, a reduced heart rate, and a bizarre preoccupation with food (source).
What if it were possible to experience the benefits that calorie restriction (CR) affords without all of the metabolic compromise and without the mental strain? It appears that intermittent fasting, or time-restricted feeding (TRF) may be the answer. I firmly believe every benefit of CR can be matched by TRF, but without the mental and physical agony of prolonged calorie restriction.
Time restricted feeding simply means consuming all food within a certain window of time. All food for the day is eaten in a period of most commonly either 1, 4, or 8 hours. When the window closes, food will no longer be consumed. Water, black coffee, and tea may be drunk ad libitum to stay hydrated and ward off hunger.
Most individuals undertake a fasting regimen to lose weight or reverse metabolic disease. Hatori et al have demonstrated that TRF can prevent metabolic disease, liver damage, and inflammation without even reducing calorie intake (source). Using TRF can affect mitochondrial physiology in neurons in the hippocampus and other brain regions by mechanisms involving increased mitcohodrial biogenesis, as well as increased mitochondrial stress resistance mediated by brain derived neurotropic factor (source). Since mitochondrial issues are at the root of aging, it appears that TRF can be just as effective as CR. Further, in regards to proinflammatory genes, even in mice fed normal diet, TRF reduced the expression of inflammatory cytokines in white adipose tissue (source). With regards to age-related neurodegeneration, TRF can enable “hippocampal neurons…more resistant to degeneration and learning..memory deficits were ameliorated” (source). So one of the other markers of aging- neurodegeneration- is also protected against by using TRF. Even pitted against CR, TRF showed a greater reduction in tau proteins and beta-amyloid plaques, “suggesting that IF (or TRF) can protect neurons against dysfunction even in the presence of A-beta and tau pathologies (source)
Time restricted feeding is as effective (perhaps even more!) as calorie restriction, and an easier protocol to follow. Seimon et al found that TRF was easier to adhere to than CR, and just as effective for weight loss (source). In finding that it is an easier protocol to stick with, it just makes sense that TRF would be used to increase health across all modalities of aging- brain deterioration, inflammation, mitochondrial dysfunction, and metabolic disease. I, for one, would much rather restrict my eating window to four hours a day and eat whatever I want while I enjoy my youth for a longer period of time. Wouldn’t you?
I find it much easier than I thought it would be. I really am not that hungry because I still eat all of my food I would normally eat when I do eat. I am not promoting calorie restriction and neither should you.
What I do
Two days a week, I'll fast for 24 hours- dinner to dinner. The rest of the time, I may fast through breakfast, or a I may eat it. I am not strict and I listen to my body.
On weekends, I eat everything my family is eating.
The goal is to reduce insulin. Reduced insulin means reduced fat storage and reduced aging. The research is there and I have read much of it.
And that brings me to my caveat:
Don't fast if
you're in adrenal fatigue (seriously. If this is you, get ahold of me first)
you're already thin
you have an eating disorder
you are not fat-adapted
you're under the age of 21
you're in your childbearing years
you've got unsupported hypothyroid issues
If you go from eating a Standard American Diet to trying to fast, you will not be happy with the results. You will feel awful. Trust me on this, please.
I can't stop you from doing this, of course. All I can do is teach you and leave the rest up to your good judgement.
You could fast if:
you're insulin resistant
you're diabetic (NOT WITHOUT GUIDANCE!)
you're weight-loss resistant
If you are diabetic and you are on insulin or glipizide or lantus or metformin, your doses are probably titrated to account for the sugar intake on a Standard American Diet. If you decide to fast for a meal or two, but you are still on the same dose of insulin, you could go into a hypoglycemic coma. You need to talk with your doctor first. Then get ahold of me and we can work on the specifics on your protocol.
While I entered into this out of curiosity, I don't know how long I will continue. I still believe that three square nourishing meals a day are best for nearly everyone.
Start there, for the love. Please start there. You may find yourself pleasantly surprised and very happy.
If you want help and supervision with learning how to properly and responsibly fast, get ahold of me.
But I will tell you again, I truly believe fasting is just a tool to be used for a purpose. Moms, do not let your daughters fast. Don't do it if it is a temptation to slip into disordered eating. The research says 2, 24-hour fasts a week are enough to enjoy the anti-aging benefits. That's really all you need. Don't get too crazy up in there.
Well, that is my research and my experience. I think you can tell that this is my verdict:
I recommend fasting for certain mentally healthy, fat-adapted populations with supervision.
Holy CYA, Batman! Haha.
What are your questions? What is your experience? LMK.