Written and medically reviewed by Nicole Grant, RD
Aging is inevitable, but the speed at which you experience its effects doesn’t need to be. Consider the age-old car metaphor: If you fill it up with poor-quality gas, neglect changing the oil, and let your antifreeze run out, your car is going to clog up and break down a lot sooner than it would with proper care. Your body is similar: When you give it the nourishment it needs, you can significantly slow down your own aging process.
How Does Your Body Shift as You Age?
“Aging” essentially refers to certain processes inside your body changing over time. These changes occur at physiological, hormonal, and cellular levels.
Physiologically, some of the biggest changes you can experience are a decrease in muscle mass and strength, loss of bone density, wrinkling skin, loss of hearing, and decreased vision. These changes can lead to less mobility, increased risk of injury, and greater insulin resistance, all of which lead to poorer metabolic health.
Hormonally, men and women typically experience a decrease in sex hormones such as estrogen, testosterone, and progesterone at around 50 years old, give or take a decade. This shift can lead to the aforementioned decreases in muscle mass and bone density and can also impact sleep, weight gain, and cognitive function.
Finally, aging leads to cellular changes, including DNA alterations, reduced mitochondrial efficiency, and imbalanced nutrient-sensing pathways. Ultimately, these changes can contribute to age-related diseases such as cancer, heart, and liver diseases and can impact your body’s ability to heal and repair itself.
Which Nutrients Should You Focus More On?
While different stages of life come with different nutritional needs (which we’ll address a little later), some nutrients remain essential throughout the lifespan, for everyone.
For instance, protein is important in all stages of life to help support the growth and maintenance of lean mass. The optimal amount for adults ranges from 1.2–2.2 grams per kilogram of body weight. Foods high in protein include seafood, poultry, meat, dairy, tofu, tempeh, and eggs.
Protein also helps you to build and maintain strong bones, which are equally essential as you age. Calcium, vitamin D, phosphorus, magnesium, and vitamin K are also crucial for maintaining strong bones. Foods like fatty fish, meat, full-fat dairy, fermented foods, leafy greens, seeds, and eggs can provide these nutrients.
Anti-inflammatory foods can also play a vital role in managing the aging process. Chronic inflammation can contribute to many age-related diseases, so including anti-inflammatory foods in your diet can help to counteract those effects. Foods rich in omega-3 fatty acids such as fatty fish, flaxseeds, and walnuts are known for their anti-inflammatory properties. Sulforaphane, found in broccoli sprouts and other cruciferous vegetables, activate antioxidant and anti-inflammatory processes in the body, as well.
Finally, nutrients that support DNA functionality can also contribute to healthier aging. Vitamin C, vitamin E, zinc, manganese, and selenium help prevent DNA oxidation, while niacin, zinc, iron, and magnesium assist with DNA damage sensing and repair. Essentially, these vitamins and minerals help your DNA stay intact, which helps maintain proper cellular function and minimizes risk of genetic mutations — in turn contributing to healthier aging and reducing the likelihood of age-related diseases and conditions. Many foods are rich in these nutrients, including fruits, vegetables, whole grains, meat, seafood, nuts, and seeds.
Which Foods Should You Try to Limit or Avoid?
While no food ever needs to be entirely eliminated from your diet, certain foods should be limited due to their tendency to promote inflammation, oxidative stress, and other aging-related changes. Ultra-processed foods, often packed with added sugars and unhealthy fats, are one prime example. These foods can promote inflammation and contribute to weight gain and related health issues such as heart disease, diabetes, and certain cancers. In addition, added sugars found in many processed foods directly affect blood sugar, and dysregulated blood sugar can interrupt cellular pathways that are crucial for healthy metabolism and glucose regulation. The best way to avoid these aging-accelerating foods — while loading up on nutrients that support healthy aging! — is by filling your meals and snacks with as many whole, unprocessed foods as possible.
How to Adjust Your Diet by Decade
Now it’s time to dive into some more nuanced nutritional needs, as dictated by your age. While certain nutrients are pretty much always essential (e.g., protein, calcium, and omega-3 fatty acids), making further adjustments according to your unique stage of life can help you further extend your lifespan and your healthspan.
Childhood and Adolescence
Due to the demands of growth and development, children and adolescents’ nutritional requirements are higher relative to their body size than at any other time in life. Calories, protein, vitamins, and minerals all play crucial roles in building a healthy body.
This stage of life is also vital for establishing healthy habits and a positive relationship with food. Statistics show that today, in the U.S., about 67% of a child’s calories are coming in the form of ultra-processed foods such as chips, hot dogs, candy, crackers, frozen foods, and sweetened beverages — so clearly there’s a lot of work to be done! It’s up to adults to start reducing that percentage and instead help children focus on minimally-processed foods such as vegetables, fruits, healthy fats, nuts, seeds and protein, which are much more nutrient-dense and better support a growing body.
20–40 Years Old
Between the ages of 20 and 40, you shift from a period of growth to a period of optimization. You’ll achieve peak bone mineral density around age 30, which means that in the years prior, you’re ideally doing everything you can to support bone development. To accomplish this, focus on foods rich in calcium, vitamin D, vitamin K2, magnesium, and phosphorus. Some examples include fatty fish, full-fat dairy, fermented foods, nuts, and eggs.
Muscle protein synthesis is also at an all-time high during these decades, since people in their 20s tend to have higher levels of anabolic hormones such as testosterone and growth hormone. The recommended dietary allowance (RDA) of 0.83 grams of protein per kilogram of body weight (g/kg) is sufficient to meet basic living requirements in 97–98% of people, but if you want to build and maintain healthy, strong muscles, it’s wise to aim higher than the RDA. For those with a BMI greater than 30 kg/m2 who are not competitive athletes or bodybuilders, a good daily protein intake target is 1.2–1.6 g/kg. Alternatively, if your BMI is under that threshold and you are exercising regularly and/or trying to lose weight, you may want to aim even higher and target 2.2 g/kg (which comes out to an even 1 g/lb).
Now is also a good time to start experimenting with fasting. Periodically limiting your intake of calories, glucose, and amino acids leads to an increase in autophagy, an important process for cellular health, particularly as you age. Play around with different protocols to get a sense of what works best for your body.
40–60 Years Old
Aging starts accelerating between the ages of 40 and 60 due to the aforementioned physiological, hormonal, and cellular shifts that are happening inside your body. The hormonal shifts in particular (which in women are known as perimenopause and menopause) increase your risk for insulin resistance, metabolic syndrome, and the chronic diseases that follow. To help combat some of this change, you’ll want to adopt a nutritional approach that balances blood sugar. Focus on creating a lower-glycemic plate filled with whole foods including vegetables, adequate protein, healthy fats, and high-fiber carbohydrates.
Fasting is also a great way to support glycemic control and balance your hormones. Try out longer or more frequent fasts, as your body allows. Work on finding a protocol that balances the need for a healthy weight — which can become more challenging during this phase of life — and allows for enough opportunities to consume sufficient protein, calories, and micronutrients to support lean mass as well as bone and brain health — all of which become increasingly important as you age.
Typically, you’ll need at least two meals per day to meet your nutrient requirements, but the length of your fast and how many meals and snacks you eat will depend on your individual needs and priorities. Longer fasts coupled with high-protein meals tend to be better for losing weight and controlling blood sugar, whereas shorter fasts with high-protein meals and snacks can suffice when weight maintenance is the goal.
60–80 Years Old
In addition to continuing nutrition habits that support bone and muscle health (which, ideally, you developed in the decades prior), you’ll want to further emphasize vitamin B12 in your diet after you turn 60.
As you age, your ability to absorb vitamin B12 declines. Vitamin B12 deficiency can show up in acute symptoms such as memory problems, but it can also impact your body’s ability to metabolize homocysteine, leading to systemic accumulation and increasing your risk of vascular disease, stroke and certain cancers. Therefore, work on increasing your consumption of vitamin B12-rich foods such as fish, chicken, oysters, clams, milk, cheese, and shiitake mushrooms.
Meanwhile, fasting is still a beneficial strategy, particularly for maintaining a healthy body weight and losing excess fat (which are associated with a decreased risk of all-cause mortality). One study looking at intermittent fasting in women over 60 showed that those who followed a 4-to-6 hour eating window were able to lose an average of 4% of their body weight in only 8 weeks.
80+
Protein, vitamin B12, and nutrients for bone and brain health remain essential in your later decades. However, shifts in taste and smell may occur, which can create challenges to getting enough of the nutrients you need. In order to encourage sufficient intake, get creative with flavor profiles and bold ingredients. Add spices, herbs, and citrus to not only enhance the taste but to give the dish a boost in nutrients, too.
Also, drink water! Water is crucial throughout the lifespan for obvious reasons (proper hydration is essential for all bodily functions), but as you age, your sense of thirst can diminish. Therefore, it’s more important than ever to be intentional about your water intake after 80 years of age.
Finally, research is limited on fasting in older adults, so you’ll need to decide whether or not to continue a fasting practice on an individual basis. Since sufficient dietary intake and nutrient absorption tend to be compromised at this age, no fasting or shorter fasts like circadian rhythm fasts lasting 12–13 hours may be appropriate if you are at higher risk for undernutrition, as this will give you more time to consume enough nutrients. Shorter fasts can also help align circadian function throughout your body, which will help you avoid age-related deteriorations in sleep quality and maintain restorative slow-wave sleep. On the other hand, certain metabolic conditions such as type-2 diabetes or severe obesity may benefit from longer fasts. It’s always best to consult with your health care practitioner or dietitian to ensure the nutrition strategy you’re adopting is safe and appropriate for you.
Conclusion
To navigate the intricacies of aging, you must understand your body’s changing nutritional needs. Keeping your body well-nourished with adequate protein, essential micronutrients, and anti-inflammatory foods will help you remain strong and resilient. Meanwhile, developing a robust fasting practice will help you accomplish the increasingly difficult (but increasingly vital) tasks of regulating your blood sugar levels and maintaining a healthy weight. In the end, every stage of life presents unique nutritional demands; however, with proper care and a balanced diet, you can give yourself the best opportunity to age with grace and vitality.
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