Your Physical Health: Is Fasting good for weight loss, and how do you do it?
Learning how — and even when — to fast can foster a variety of health benefits when done correctly.

Good afternoon!
After taking a short break from writing and reverting to reading, I read a passage from a book I’m chipping away at that inspired today’s post. Fasting — the action of restricting food intake for various health outcomes — is prevalent in today’s fitness and nutrition dialogue. The method of eating fewer meals, sometimes as few as one a day, has been popularized by celebrities and fitness gurus as a means of losing weight or maintaining a lean figure.
Thankfully, we non-celebrities seem to finally be catching on to the idea that maybe fasting like the celebrities do is not the way to get in shape. To the layperson, it seems as though the rationale checks out: eat less, exercise more, lose weight. Right? In theory, the process works, but in practice, it can be hard to replicate. The availability of all the right foods we need to lose weight while fasting isn’t guaranteed. The low-stress environment we need to optimize our metabolism certainly isn’t promised, either.
The most popular fasting method — Time Restricted Fasting
Still, that’s not to say fasting doesn’t work. It can, and it does, when done correctly. And I think it’s time to clear the air about all the different ways you can fast.
In my experience, clients and friends alike get caught up in the 16/8 method. It involves a 16-hour time-restricted fasting period (ideally starting after dinner, lasting through sleep and the following morning) and an 8 hour eating window. The problem with this method is that calories consumed don’t always tend to drop in the 8 hour eating window.
In fact, sometimes intake stays the same or even increases due to the initial stress time-restricted fasting puts on your appetite to eat the amount of food you’re used to.
Another drawback to time-restricted fasting is that some individuals need more time than others to go into ketosis. Ketosis, which is the process your body utilizes to convert fat cells into energy, can happen anywhere between 12 and 24 hours of fasting. That’s a pretty large window of experimenting to find out when your body is burning fat during your first attempts at time-restricted fasting. Also, ketosis can feel like a worse version of hunger pangs in some cases. It can cause brain fog, headaches, and upset stomachs.
Time-restricted fasting for long periods of time can dampen the immune system’s effect on the body for a short time before strengthening it again, which can explain the side effects in some indivduals who fast.
So since we can’t make 16 and 8 your magic numbers for fasting, we have to look at other methods if this “eating window” strategy fails. Also, while I have your attention (hopefully I still do at this point), please, consult your doctor before attempting any fasting regimen. Please.
Getting a bit unconventional
Enter fasting-mimicking. In The Angel and The Assassin, a scientific deep-dive on brain health and the cells that tell the story of both our mental and physical health, Donna Jackson Nakazawa explains how fasting-mimicking diets performed on mice resulted in a rebuilding of myelin in mice. Myelin, a protein-fat mixture that coats nerve fibers and protects the spinal cord, is the first line of defense against neurological afflictions like multiple sclerosis.
The findings of fasting-mimicking in mice and the ensuing diet plan that came from it — Prolon — showed that with the right foods, you can not only continue to eat on your regular schedule, but simply reducing a few hundred calories per meal is an equally effective form of fasting that can reap benefits for immune health, too.
The Prolon diet is just one example, but since my fiancee has tried it herself, here’s my synopsis: appetite can be reduced without actually cutting out meals or even changing your meal time. But these reduced-calorie or reduced-serving foods must be intensely packed with nutrients. You may even consider a multivitamin with this diet adjustment if you’re not going to go full throttle into Prolon.
Analyzing your current diet and honestly assessing how much of it you could do without is the first step to creating your own fasting-mimicking diet. Fasting-mimicking isn’t recommended if you easily get cranky, irritable, or feel physically unwell from drastic changes to your diet.

Intermittent Fasting — the real intermittent fasting
The subheading above felt necessary because I speak to a lot of individuals who’ve undertaken their own fasting routine without medical consultation and confuse the type of fasting they’re engaging in. Time-restricted fasting and intermittent fasting often get confused, but intermittent fasting simply involves staggering your caloric intake throughout the week. It burns fat in the same way that the fad-driven low-carb and keto diets do, and you won’t have to miss out on nutrients in the process.
A popular method for intermittent fasting is the 5:2 ratio, which involves eating regularly for five days of the week, and dramatically scaling back calories on the other two days. On those days, the reduction in calories should be significant. If you’re typically eating 2000 calories a day, a target restrictive day would be somewhere around the 1200 calorie mark (or lower, depending on your tolerance).
This method can be easier, more sustainable, and more easily scalable. Although Nakazawa doesn’t specifically mention intermittent fasting in her book, I’m willing to bet that this method can also reap similar immunological benefits to fasting-mimicking.
This method, as with the others, still requires a nutrient-dense diet, and limitations around processed food consumption while engaging in it.
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