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4 Lifestyle Habits For A Longer Life

Andrew Merle
Oct 1 · 7 min read

I am always looking for ways to maximize health and longevity.

There isn’t anything I can do about my genes, but research shows that only 20% of how long we live is dictated by genes, whereas the other 80% is dictated by lifestyle.

Therefore I am most interested in the lifestyle habits that lead to a long and healthy life.

Fortunately, one of the world’s leading longevity experts recently revealed his findings after 25 years of research on aging.

David Sinclair, PhD, is one of the world’s most renowned scientists, best known for discovering why we age and how to reverse it. Dr. Sinclair is a Professor of Genetics and co-Director of the Paul F. Glenn Center for the Biology of Aging at Harvard Medical School, and he has been named by Time magazine as “One of the 100 most influential people in the world” and among the “Top 50 People in Healthcare.”

In Dr. Sinclair’s new book Lifespan: Why We Age — and Why We Don’t Have To, he distills a quarter-century’s worth of research into some simple things we can do to live longer.

These tools and tactics are available to nearly everyone, regardless of age, location, or socioeconomic status.

1. Fasting

Calorie restriction is incredibly powerful for longevity.

“After 25 years of researching aging and having read thousands of scientific papers, if there is one piece of advice I can offer, one surefire way to stay healthy longer, one thing you can do to maximize your lifespan right now, it’s this: eat less,” says Dr. Sinclair.

You don’t need to constantly deprive yourself — even once-in-a-while calorie restriction yields tremendous health benefits.

Specifically, a periodic 5-day calorie-restricted diet called a Fasting Mimicking Diet has been shown to rebuild the body at the cellular level. The diet (developed by another top longevity expert, Dr. Valter Longo) calls for about 1100 calories on day one and 800 calories per day on days 2–5, consisting primarily of vegetable soups, low-sugar energy bars, and supplements.

People who completed this program once a month for a period of three months lost weight, reduced body fat, lowered blood pressure, and had lower levels of a hormone called IGF-1 (low levels of IGF-1 have been closely linked with longevity). An average person could complete this protocol 3–4 times per year and expect measurable anti-aging benefits.

There are other popular fasting methods these days, including skipping breakfast and having a late lunch (the 16:8 diet), eating 75% fewer calories for two days a week (the 5:2 diet), skipping food altogether for a couple days per week (Eat Stop Eat), or — on the more extreme end — not eating at all for an entire week each quarter, as longevity guru Dr. Peter Attia does.

“Over time, some of these ways of limiting food will prove to be more effective than others,” says Dr. Sinclair. “However, almost any periodic fasting diet that does not result in malnutrition is likely to put your longevity genes to work in ways that will result in a longer, healthier life.”

The earlier you start a fasting protocol the better, says Dr. Sinclair — perhaps after age 40, when molecular decline really starts to take effect.

Dr. Sinclair (who is 50) personally skips a meal or two each day, but that is primarily due to his busy schedule as opposed to a conscious effort. Lunch is the meal he skips most often.

2. Eat A Low-Protein, Vegetable-Rich Diet

When you do eat, you want to focus on vegetables, legumes, and whole grains, and limit meat, dairy, and sugar. That is the dietary pattern of centenarians in all of the Blue Zones, the places around the world where people live the longest.

Photo by Anna Pelzer on Unsplash

“There isn’t much debate on the downsides of consumption of animal protein,” says Dr. Sinclair. Study after study has demonstrated that heavily animal-based diets are associated with high cardiovascular mortality and cancer risk.”

He says processed meats such as hot dogs, sausage, ham, and bacon are especially problematic, with hundreds of studies showing a link between these foods and colorectal, pancreatic, and prostate cancer.

That doesn’t mean you need to stay away from red meat altogether. Our hunter-gatherer ancestors ate a plant-heavy diet, but they did consume some red meat and fish in moderation. But in general, you should opt for plant protein instead of animal protein if you want to live longer. Meat and dairy — and to a lesser degree chicken, fish, and eggs — all activate an enzyme in the body called mTOR, which is associated with shorter lifespan. Not surprisingly, it has been shown that vegetarians suffer lower rates of cardiovascular disease and cancer than meat eaters.

Dr. Sinclair recommends only eating animal protein when recovering from physical stress or injury. He personally eats mostly plants and avoids eating other mammals, but he will occasionally eat meat on days when he works out. He also minimizes consumption of sugar, bread, and pasta (he gave up desserts at age 40 but does steal tastes from time to time).

3. Exercise

Calorie restriction and eating a low-protein diet puts our bodies into a beneficial state of nutritional adversity, but Dr. Sinclair says physical adversity is also important to trigger our survival circuits and prolong longevity.

Exercise puts a productive level of stress on the body, shifting cells into survival mode and causing us to grow back stronger. People who exercise just 150 minutes per week — the equivalent of a half hour of jogging five days a week — have been shown to have aging markers that are 9 years younger than those who have a more sedentary lifestyle.

Another recent study showed that running just 4–5 miles per week — which can be achieved in less than 15 minutes per day for the average person — reduced the chance of death from a heart attack by 40% and all-cause mortality by 45%.

But not all exercise is created equal — intensity does matter. “It’s high-intensity interval training — the sort that significantly raises your heart and respiration rates — that engages the greatest number of health-promoting genes,” according to Dr. Sinclair.

He says you’ll know when you are doing this level of vigorous activity when it feels hard — your breathing will be deep and rapid at 75–80% of your maximum heart rate, you’ll be sweating, and you won’t be able to say more than a few words without pausing to catch your breath. This level of physical exertion activates the body’s defenses against aging but stops short of doing any permanent harm.

Dr. Sinclair’s personal exercise routine includes going to the gym most weekends for weight lifting and jogging. He also walks a lot throughout the day and takes the stairs whenever possible.

“Exercise turns on the genes to make us young again at a cellular level,” he says. “Would a combination of fasting and exercise lengthen your lifespan? Absolutely,” concludes Dr. Sinclair.

But there is still more we can do.

4. Cold/Heat Exposure

Exposure to uncomfortable temperatures is another proven way to activate your longevity genes.

When we are taken out of our temperature comfort zone, our survival response is engaged, causing changes in our breathing pattern, blood flow, and heart rate.

Specifically when we are uncomfortably cold, we activate protective brown fat in the body. In fact, it has become clear that calorie restriction has the effect of reducing core body temperature (it seems all our longevity mechanisms are linked).

Photo by Yann Allegre on Unsplash

Additional “cold therapy” can be achieved by simply going for a walk in a t-shirt on a cold winter day, leaving a window open overnight while you sleep, or taking a cold shower. In particular, exercising in the cold supercharges the production of beneficial brown fat.

But moderation is important. “Similar to fasting, the greatest benefits are likely to come for those who get close to, but not beyond, the edge,” says Dr. Sinclair. “Hypothermia is not good for our health. Neither is frostbite. But goose bumps, chattering teeth, and shivering arms aren’t dangerous conditions…and when we experience these conditions often enough, our longevity genes get the stress they need to order up some additional healthy fat.”

Heat exposure has benefits as well, but the way it works is less clear. We know that frequent sauna users have reduced rates of heart disease and premature death, but we don’t know exactly why.

“Either way, one thing is clear: it does us little good to spend our entire lives in the thermoneutral zone,” says Dr. Sinclair. “Our genes didn’t evolve for a life of pampered comfort.”

On days when he goes to the gym, Dr. Sinclair has a personal practice of hanging out in the sauna and then dunking in an ice-cold pool. He also tries to stay on the cool side during the day and when he sleeps at night.


These 4 lifestyle habits — Fasting, eating a low-protein diet, exercise, and cold/heat exposure — all produce a mild kind of stress on the body that activates cellular defenses without causing too much damage.

It turns out that not all stress is bad — we just need to use it to our advantage.

These simple anti-aging practices are available to all of us today, regardless of where you live, how old you are, or how much money you make.

There are plenty of technological and pharmaceutical advancements on the horizon — and Dr. Sinclair details what’s coming in in his book — but we can get started with what’s in our control right now. There is only upside.

“Ten additional healthy years is not an unreasonable expectation for people who eat well and stay active,” says Dr. Sinclair.

I hope these tips help you achieve a life of prolonged health and vitality.

Andrew Merle

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I write about healthy living. Subscribe to my email list at andrewmerle.com.

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