How The Keto Diet Plays A Role In Living Longer


The Ketogenic Diet, or Keto for short, has gained in popularity due to its reported ability to help various ailments while leading to substantial weight loss. But what exactly is the keto diet and how does it help people live longer? The team at spermidineLIFE® takes a closer look at this popular diet, including the dos and don’ts and how it affects the aging process


Bowl with healthy salad full of vegetables and meats consistent with a keto diet

Keto Diet Explained

The Keto Diet is a low-carb, high fat diet that is touted to have benefits against diabetes, cancer, epilepsy and Alzheimer’s disease. It has some similarities to Atkins and other low-carb diets. Ketosis happens when your body doesn’t have enough carbohydrates to burn for energy. Instead, your body will begin to burn fat, creating ketones, which are used for fuel. As you can imagine, this process is very beneficial for those looking to lose weight. The Ketogenic diet is the only diet that can be measured.  Ketones can be measured in blood, urine or breath.

Typically, the Keto Diet is 70% fat, 25% protein and 5% carbohydrates.

The low-carb portion puts the body into a metabolic state known as ketosis. This is when the body becomes very efficient at burning fat for energy. The fat is also turned into ketones in the liver, which help supply energy to the brain.  Blood sugar and insulin levels are drastically reduced on the Keto Diet.

The Keto Diet has been found to help people with a variety of health ailments including:

  • Diabetes - Those who are diabetic or pre-diabetic are able to lose excess fat which is closely tied to type 2 diabetes, pre-diabetes and metabolic syndrome. Some people on the Keto Diet were even able to reduce or eliminate diabetes medication.
  • Heart Disease - Risk factors like body fat, HDL cholesterol levels and blood pressure were improved on the Keto Diet.
  • Cancer - Research is underway on the impact of the Keto Diet to slow tumor growth.
  • Alzheimer’s Disease - Symptoms may be reduced as well as progression of the disease.
  • Epilepsy - Epileptic children on the Keto Diet have seen a reduction in seizures.
  • Polycystic Ovary Syndrome - The Keto Diet can reduce insulin levels, which pay a role in polycystic ovary syndrome.
  • Acne - Eating less sugar, processed foods and lower insulin levels may help improve acne. 
Woman cutting an avocado consistent with a ketogenic diet

Measuring Ketones 

Ketone levels are something people tend to focus on when starting a Keto Diet. It’s important to understand it, but not let it overwhelm you.  Optimal ketone levels will vary depending on your goals.

Here is a breakdown on levels:

  • 0.5 mmol/L – when ketosis begins
  • 0.5 mmol/L - 1.0 mmol/L when ketosis is considered light, but still good
  • 1.0 mmol/L through 3.0 mmol/L – ketosis is considered optimal

For weight loss, starting at the beginning point and going to the optimal range is ideal. If people are looking for therapeutic benefits for medical purposes, then being in a higher ketone range of 3.0 mmol/L – 5.0 mmol/L range is ideal.

The optimal range is considered optimal because there is where people should be for weight loss and general health reasons.

How Long Is It Safe To Be In Ketosis?

The first couple of weeks being on the Keto Diet is more of an adjustment phase where the body is getting used to relying primarily on fat versus glucose or carbohydrates. Currently, there aren’t any long-term studies on the ketogenic diet so more research is needed. 

When the body first enters ketosis, people may experience symptoms similar to the flu. Symptoms can last a few days to a few weeks.

One of the biggest challenges people face on the Keto Diet is sticking with it. If someone caves in and eats a bowl of pasta, the body will fall out of ketosis and the process has to begin all over again. The Keto Diet is more of a lifestyle change than just a diet.

What Happens When You Don’t Eat For 12 Hours? 

If you fast for 12 hours, your body enters the ketosis stage. During the first 8 hours of a fast, the body will continue to digest the last food a person ate. The body will continue to function as though a person will be eating again soon.

At 12 hours, the body starts to break down and burn fat. Some of this fat is used by the liver to produce ketone bodies which serve as an alternative energy source for cells when glucose isn’t available.

What Happens When You Don’t Eat For 18 Hours?

At 18 hours, the body switches to fat-burning mode and is generating significant ketones. This is typically where a blood measurement can detect ketones in the plasma. The body begins to reduce inflammation and repair damaged DNA as well.

What Can’t You Eat On Keto?

A lot of popular foods are on the “do not eat” list while on the Keto Diet. Here is a breakdown on what to avoid:

  • Grains
  • Sweetened yogurt
  • Juices
  • Honey or syrup
  • Sugar
  • Chips and crackers
  • Baked goods
  • Starchy vegetables like corn and potatoes
  • High-sugar fruits like bananas and grapes

An autophagy diet plan consists of lowering carbs and eating more fats and protein to trick the body to use what it is already storing instead of breaking down another intake of glucose. Adding coffee, green tea, ginger, garlic, pomegranate and elderberries are all thought to increase autophagy.

Who Should Not Do Keto? 

The Keto Diet isn’t for everyone. And it’s important to check with your doctor before starting it. Those who should avoid the Keto Diet include anyone with issues of:

  • Pancreas
  • Liver
  • Thyroid
  • Gallbladder

The Keto Diet can also cause low blood pressure, kidney stones, constipation and, in some cases, an increased risk of heart disease. Pregnant and nursing women should also not do the Keto Diet.

Keto Autophagy

Autophagy is the body’s way to get rid of damaged cells in order for new, healthy ones to be regenerated. It comes from the words “Auto” meaning self and “Phagy” meaning to eat. So autophagy means to self-eat.

While it may sound terrifying, it is actually quite beneficial. The purpose of the autophagy process is to self-regulate back to optimal function.

Two ways to increase autophagy are intermittent fasting and a ketogenic diet. When the body goes into ketosis, it’s like the body is fasting, meaning it is using up those old damaged cells, without actually being in a fast.


couple making a keto friendly meal

Benefits Of Autophagy

There are a few major benefits to autophagy due to its purpose of cell renewal. One of the biggest benefits of autophagy is that it is anti-aging since its purpose is to clear out the old, damaged cells for new and healthier ones. 

Autophagy also helps the body in times of starvation because the body is able to keep going by breaking down cellular material to use for necessary bodily purposes. Since it removes toxic proteins from cells, it can help protect people from Alzheimer’s and Parkinson’s disease.

It also has the potential to protect people from cancer. Without autophagy, cells that no longer work or are damaged could multiply which is a baseline for cancerous growths.

When Does Autophagy Start?

It is difficult to measure autophagy outside of a lab, but many experts believe the autophagy process begins in humans after 18-20 hours of fasting. Being deprived of nutrients is what triggers autophagy. After 14-16 hours of fasting, glycogen levels in the liver are low and autophagy is introduced.

When Does Autophagy Peak?

The maximum autophagy benefits happen after the 48-72 hour mark is reached. For some people, it isn’t easy to go that long without food. This is why intermittent fasting has become so popular. It is a way for the to use up its energy stores, without the length of time required under most types of fasts.

Can Autophagy Reverse The Effects Of Aging?

Autophagy helps the body’s cells to stay in balance by removing cells that are no longer functioning properly or at all. This helps the body in several ways including metabolically, protecting against certain diseases and illnesses as well as its anti-aging properties.

Aging is the degradation of cells so autophagy’s process of breaking down the damaged cells so new healthier ones can be formed helps slow the aging process from the inside out. Aging isn’t just physical. It is also how our body is doing internally as well. And autophagy helps to fight age-related diseases as well.

What Supplements To Take When Fasting?

Our body is made up of cells. And they must function right for us to be healthy. Our body’s natural way to rid itself of old, damaged cells is through autophagy which typically happens from fasting or eating a keto-friendly diet.

As we age, our body doesn’t replenish cells the way it used to and sometimes it needs a little help. That’s where supplements come in. Spermidine can help activate the autophagy process in our body.

Spermidine is a polyamine and while we can obtain it from foods, the modern diet rarely contains enough to replenish it especially as we age. Providing the body with spermidine supplements can help assist the body’s own autophagy process for cell rejuvenation

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  • Don Moxley - Director of Applied Science

    Don Moxley is the Director of Applied Science at Longevity Labs. Moxley draws upon his career as an athlete, a sports scientist, and an instructor to lead and educate on the science of autophagy and longevity.