Having just wrapped up the holidays, there have been several days these last few weeks where what I ate (and how much I ate) made me feel sick, sluggish, and bloated.

It made me think back to the good old days of high school where I could eat just about anything I wanted to, and it had minimal impact on how I felt. What I wouldn't give to have that now!

But whether you feel it or not, what you eat and how much you eat has a profound impact on your physiology. Within a matter of seconds after consumption, what you eat begins to be broken down into the fundamental components that fuel every function in your body. You are laterally what you eat.

And while you can maybe think of a few anecdotes of people you know eating poorly but living to an old age, the data speaks differently. By and large, nutrition and proper diet plays a very critical role in how long you live and how healthy you are along the way.

But what does "nutrition" even entail? How does it actually impact longevity? And what does a longevity diet look like?

That's what we're here to answer. Read on...

What does "nutrition" entail?

(I know this section is a little long, but it is important that you have a solid base in what "nutrition" is!)

Nutrition is the process of consuming food and liquid to fuel all the metabolic processes your body needs to keep you alive. Though it has strong interplay with pharmacology (medicine) and exercise, it is distinct from these other areas.

Nutrition is broken down into three main categories: macronutrients, micronutrients, and hydration.

Macronutrients

These are nutrients that you need relatively large amounts of (compared to micronutrients) in order to survive. These macronutrients can be used or stored as fuel, used for a variety of metabolic processes, and serve as the primary building blocks of cells.

Macronutrients are broken into three main categories as well, including carbohydrates, proteins, and fats.

• Carbohydrates: They are the primary source of energy for the body. Carbohydrates are found in foods like bread, rice, pasta, fruits, and vegetables. They are broken down into glucose, which is used by the body's cells for energy. Carbohydrates can be classified into simple (sugars) and complex (starches and fiber), with complex carbs generally considered healthier due to their slower digestion and more sustained energy release.
• Proteins: Proteins are essential for growth, repair, and maintenance of body tissues. They are made up of amino acids, some of which are essential and must be obtained from the diet. Protein is found in animal products like meat, fish, and eggs, as well as in plant-based sources like beans, lentils, and nuts. They are crucial for building muscles, enzymes, hormones, and other vital body components.
• Fats: Fats are a concentrated source of energy and are essential for various bodily functions, including nutrient absorption, nerve transmission, and maintaining cell membrane integrity. Fats can be saturated (typically found in animal products and some tropical oils) or unsaturated (found in nuts, seeds, fish, and vegetable oils). Unsaturated fats are generally considered healthier, especially omega-3 and omega-6 fatty acids, which are essential fats not produced by the body.

Each of these macronutrients has a different level of energy it can provide to the body (as measured in calories). These are:

• Carbohydrates: Approximately 4 calories per gram.
• Proteins: Approximately 4 calories per gram.
• Fats: Approximately 9 calories per gram.

These are only approximate values since different forms of each can have slightly different energy potential.

Whatever isn't used for energy during activity is then stored away for future energy use or used in other metabolic processes.

Micronutrients

These are nutrients that you need relatively little of (usually measured in milligrams vs. grams for macronutrients), but they are still of vital importance to health and longevity. Though they are not consumed as fuel, they play a key role in metabolic processes including the production of hormones, neurotransmission, metabolizing food, transporting oxygen, and much much more.

The primary categories of micronutrients are vitamins and minerals.

• Vitamins: These are organic compounds derived from plants, animals, and microorganisms, and can even be made synthetically in some cases. They can either be fat-soluble (like vitamins A, D, E, and K) or water-soluble (like vitamin C and all the various B vitamins), which affects the way you are able to obtain or absorb the vitamin. It is also important to know that some vitamins go by other names, such Niacin for vitamin B3 or Ascorbic Acid for vitamin C.
• Minerals: These are inorganic compounds that can primarily be found on the period table of elements. These include calcium, iron, zinc, magnesium, sodium, and potassium, among many others.

For both vitamins and minerals, a balanced diet will get you most of what you need. Supplementation is only necessary if genetic mutations or other environmental factors cause deficiencies that cannot be made up for by a balanced diet.

Hydration

Not too many people think of hydration as being part of nutrition, but it has a very important role to play.

Water is crucial for all processes within cells, especially due to it's ability to dissolve, diffuse, transport, and bind nutrients together. Nothing gets done without sufficient water.

Why is nutrition important for longevity?

Nutrition is not only a vital part of staying healthy while young, but also for living to an old age while staying healthy.

You can think of nutrition as vital for longevity in two ways: it's ability to prevent disease and the slowing of aging processes.

Preventing Disease

What you eat has an outsized effect on what diseases you might develop in life. Specifically, poor nutrition leads to a number of diseases that are the top causes of natural death in the United States.

Here is more detail on the role of nutrition in those top causes of natural death, along with the annual death rate in the United States (as of 2021).

What does a longevity diet look like?

There are three main pillars of nutritious eating that will increase the chances of you living a long and healthy life. These are: balancing macronutrients and caloric intake, getting sufficient micronutrients, and drinking plenty of water.

The good thing is, this has been standard advise for many years, so you don't need to worry about this changing much over time.

Let's walk through each of these elements.

Balancing Macronutrients and Caloric Intake

Because macronutrients are the source of your calories/energy, is is important to balance your intake with your level of activity. Running a calorie surplus (consuming more calories than you burn) will cause you to slowly gain weight, likely in the form of fat. It should be no surprise that excessive fat stored for long periods of time puts stress on the body and can lead to a number of the diseases.

Running an excessive calorie deficit, on the other hand, will cause you to lose weight both in terms of fat and eventually muscle tissue. This can put undue stress on your body and reduce muscle mass which will have a big impact on your healthspan.

So, unless you are in a state of needing to lose fat or gain muscle weight, you shouldn't be running a calorie surplus or significant deficit for long periods of time.

The other aspect of balancing macronutrients is eating a mix of all macronutrients, while trying to find "healthier" sources of each type of macronutrient.

Some people will say that you should try a carb-free or fat-free diet, but these are essential macronutrients that you should never try to eliminate completely (if that was even possible). Your total caloric intake should be comprised of a mix of these macronutrients in a way that matches your current state of activity as well as your genetics.

It can be argued, though, that you should try to avoid certain types of carbs and certain types of fat while trying to maximize other types of both. Specifically, diets high in added sugar and saturated fats have been clearly linked to diabetes and heart disease. On the other hand, diets high in fiber (another type of carbohydrate) and omega fatty acids will provide you a number of health benefits while avoiding the downsides of the other types.

Getting Sufficient Micronutrients

There is no need for me to go into the details of each micronutrient and how much you need of each, but here are some general guidelines to increase the likelihood that you have sufficient coverage of all of them.

• Eat plenty of plants: Diets high in vegetables, fruits, nuts, and seeds (vs. dairy, meat, and sugar) are one of the most common features of blue zones. Plants carry a high concentration of vitamins and minerals that are difficult to get from other sources.
• Eat fresh foods: Many micronutrients, including vitamin A, B, and C, can degrade with exposure to light, air, and heat. To increase the nutrient density of the foods you eat, choose foods that were recently harvested and with minimal processing.
• Eat a variety foods: Variety is probably the most important aspect of getting sufficient micronutrients. Not all plants or other foods are created equal in the types and amounts of each micronutrient they carry. Rotate through a wide range of vegetables, fruits, seeds, and meat options, and look to get a variety of different colors in the meals you eat.

Hydration

Don't skip on hydration. Always have a filled water bottle nearby and constantly sip on it throughout the day. It is pretty difficult to drink too much water, though it is possible.

Adult males should aim to get 1 gallon of water (128 fluid oz) each day.

Adult females should aim to get 0.75 gallons of water (96 fluid oz) each day.

A few other important notes here:

• Soda doesn't count (as much): Sodas with caffeine can pull water out of your body, making them a less effective source of hydration. Not to mention the high amount of sugar and dyes that can cause other issues.
• Get in ample electrolytes: Sodium, magnesium, and potassium are the main electrolytes you need to be consuming to be able to hold onto the water you drink. Otherwise, you urinate most of it out or even start to pull additional water out of your body.
• Drink clean water: The water from your tap likely contains heavy metals and other undesirable solutes. Get a good filter and drink most of your water from that.

Conclusion

Nutrition is a key part of longevity. It serves as a vital lever in preventing diseases and the other hallmarks of aging.

But nutrition is not only about what you shouldn't be consuming, but also (and maybe even moreso) what you should be consuming.

Focus on eating a balance of macronutrients, eating a variety of fresh plants, and get in plenty of water on a daily basis. If you consistently stick to these three things, you are likely to live a long and healthy life.