If you want to control your weight, prevent diseases like diabetes and cancer, and extend your lifespan, that simple rule mentioned in the title is one that researchers are finding produces big rewards. For years, scientists have seen that a calorie restricted diet significantly extended the lifespan and reduced the chances of developing age-related diseases in animals like rats, flies, and nematodes. While this was exciting, researchers found it hard to study if this also worked in humans since most calorie-restricted people tended to be malnourished. It’s difficult to find people willing to forego the abundant food in our modern world for decades with the hope that it may eventually work, so most of the research continues to come from animal models.
However, the concept of intermittent fasting has been gaining in popularity lately because it also shows promise in humans, and it’s a little easier to stick with. By alternating periods of normal consumption with extended fasts, people have been able to lose weight, reduce inflammation, and improve insulin sensitivity, and animal studies show that it also may bestow the same benefits of an extended lifespan and decreased disease risk like with continuous caloric restriction. Unfortunately, a lot of these fasting protocols are still a bit too demanding for the average person. Some popular methods like the 16/8 Method (16 hour fasts), alternating day fasts (eat normal one day, fast the next), and the warrior diet (fast 20 hours then eat one large meal) really ask a lot of your willpower. They may work, but I don’t know anyone that has ever stuck to one of these intermittent fasting regimens long term. I’m not into fads, and if it’s not possible to stick with something the rest of your life, then ultimately this is just another fad diet.
Fortunately, there is a form of intermittent fasting that provides the same benefits, it works with your body’s natural chemistry already, and it’s not nearly as extreme so it’s far easier to stick with it for the long run. Instead of adopting a crazy fasting schedule, simply don’t eat after 7 PM and then fast until 8 AM the next day.
Every time you eat, you inflict damage to your body. It’s something we don’t really think about because we need food to survive (and because there’s no immediate pain), but it’s unfortunately true. The chemical processes involved in metabolism release free radicals and reactive oxygen species into your system. These highly reactive molecules then inflict damage to your cells and DNA. This damage compounds over time which not only contributes to aging but age-related diseases like cancer, heart disease, and dementia.
Your body produces antioxidants to counter this side-effect of metabolism, but studies in snakes found that the increase in free radicals after eating far outweighs the increase in antioxidants. This happens because your immune system also fires up every time you eat in order to deal with all the invading microbes you consume.
Free radicals have their place in the ecosystem that is your body. They can act as signal molecules that trigger positive adaptations. For instance, exercise produces a lot of reactive oxygen species, but in response, your body creates more mitochondria (the power plants of your cells) to deal with them. In this case, free radicals trigger your body to get more fit. Unfortunately, frequent eating doesn’t have this same benefit. It simply creates more free radicals than your system can deal with.
You can reduce the damage by eating fruits and vegetables rich in antioxidants with each meal. It’s one of the big reasons why plant-based diets (or at least diets higher in plants) tend to result in lower overall mortality rates. Remember, it’s also important to get enough vitamins and minerals so that your body can repair any damage caused by free radicals.
I bring this up to demonstrate how we have it wrong on food. We think we need to constantly eat to be healthy, keep our metabolisms up, and prevent muscle loss, but it’s the opposite. We evolved to handle periods of starvation and going without food every now and then doesn’t hurt you. I’m not trying to recommend starvation diets or any kind of extreme behavior, but we’ve adopted a belief that constant eating is necessary and that’s simply not true.
Insulin fuels cancer growth
When it comes to diseases like cancer, there are two separate pieces that help assemble this terrible puzzle. One piece is the accrued DNA damage like I mentioned in the article about how vitamins and minerals repair DNA damage. Oxidative damage builds up over time. Most of the time, the damaged cells simply die off and never cause problems, but stick these damaged cells into a sea of growth hormones and sometimes they take off and spread uncontrollably.
I talk a lot about insulin because of it’s role in shuttling sugar into muscle cells and signaling fat cells to store consumed fat, but it’s also an important growth factor. Another role of insulin is to increase protein synthesis and DNA replication. It’s why body builders eat so much rice with their protein. Insulin creates an environment that encourages growth.
Unfortunately, insulin also helps damaged cells and DNA flourish. Colorectal, pancreatic and breast cancer are strongly associated with diabetes and high insulin levels. In fact, when researchers want to grow breast cancer cells in the lab, they add insulin to the tissue culture. Then when they remove the insulin, the cancer cells die. This is why many doctors prescribe the diabetes-controlling drug metformin (which also lowers insulin levels) as a way to treat and even prevent the development of cancer in high-risk individuals.
Cutting fuel encourages recycling
We evolved to thrive in environments where food is scarce. One of the clever ways your body keeps going when it doesn’t get enough calories is by activating a process called autophagy, which literally means self-eating. This may sound like a bad thing, but it’s actually an important way that your body cleans out dangerous tissues to make way for healthy ones. Think of it as spring cleaning for your cells. Another way to think of it is as a true cleanse.
Besides improving insulin sensitivity, intermittent fasting improves your health by cleaning out damaged and senescent cells. Instead of damaged cells growing into cancer cells or senescent cells building up and causing chronic diseases like osteoarthritis, your body seeks out damaged tissue and breaks it down to be recycled for fuel and building blocks to create new, healthy tissue.
The problem with continuously eating is that it never forces your body to activate this important defense mechanism. Cellular damage is unavoidable, but if your body never cleans out these harmful cells, they will just sit there and wait to cause problems later (especially if they sit in a sea of insulin that encourages them to grow and spread).
Cut the fuel source half the day
So does this mean you need to starve yourself every other day to stay healthy? Absolutely not. You can get the benefits of intermittent fasting if you work with your body instead of against it.
As I mentioned before, your circadian rhythms determine your insulin sensitivity. You’re more sensitive to insulin in the morning, and your muscle cells become insensitive to insulin at night. Your body will still release plenty of insulin at night to deal with consumed sugars, but it will sit there in your system much longer because your muscle cells aren’t listening. So it’s not getting the sugar out of your system (which is also harmful), it’s telling your fat cells to store body fat and worse yet, it’s encouraging damaged cells to reproduce. Fasting at night will prevent you from bathing your system in harmful insulin and it will give your body time to clean out bad cells. One interesting study found that women in remission for breast cancer reduced the likelihood of recurrence by 40 percent simply by fasting from 7 PM to 8 AM. This is significant because this group demonstrated they already had the damaged cells that caused cancer before and yet they were able to cut their risk significantly with this pretty easy to follow protocol.
Don’t fight your body’s clock
The problem with a lot of the popular fasting methods like those I mentioned above is they ignore your circadian rhythms. One of the big benefits of fasting is it improves your insulin sensitivity, but many fasting methods ignore the times when you’re most insulin insensitive, which forces you to work harder unnecessarily. Why fast all day and then eat at night? Why fast during the times when you’re most active? Why fast during the times when you’re surrounded by other people that are eating? Doesn’t it make sense that the easiest way to fast would be to do it a little bit while you’re awake and then go to sleep? To really improve the benefits, you can even do a light workout in the morning before you end your fast. Exercise is another stimulus that activates autophagy and encourages your body to recycle damaged cells.
It’s like I say with steady state exercise versus high intensity training. Ultimately any kind of exercise works, but if you can get the same benefits in half the time (or much less), why not switch to the easier method. You don’t need to make this a personal challenge to test your willpower. It will take a little adjustment to get used to at first, but working with your body instead of against it will allow you to significantly improve your health and control your weight.