If you’re past the age of 40 and still eating like the young slip of a thing you used to be (before time, life and your 15-year college reunion), aging experts would like to have a word.
While being in your 40s puts you clearly in what might be called “middle adulthood,” the specter of old age is looming on the horizon. The good news is that how you handle the next few decades can play a role in the type of old age you end up having.
We talked to experts in the study of aging and longevity to see what eating habits they noticed in their liveliest, sprightliest patients. They offered up some ideas about ways to fill your plate now to set yourself up for more daily energy and vitality now, as well as for a rich and ripe old age a few decades in the future.
Science says your 40s are a good time to start eating more nutritiously.
Think you’ve got plenty of time before protecting your old age? Actually, these experts say your 40s are a great time to start laying a base of more nutritious choices, because what you start (or stop) doing now could extend your life expectancy significantly.
Dr. Amit Shah is a geriatrician and internal medicine physician at Mayo Clinic. He pointed to a modeling study whose results were published in the “Public Library of Science,” a peer-reviewed, open-access medical journal. “The study concluded that 40-year-olds switching from a typical Western diet to an optimal diet, with increased legumes, nuts and whole grains, along with less red meat and processed meat, could increase life expectancy by approximately 10 years for women and 11.7 years for men.”
The top four longevity foods, plus a little treat:
Adding 10 years or more to your lifespan means more years to blow out birthday candles, go on vacation, take long walks with friends and spend time with grandchildren. Interested? Shah already mentioned a few examples of “optimal diet” choices that could help you get there, and we followed up by asking about specific foods and eating habits that might make the biggest difference. Here are the experts’ top picks:
#1 – Food to eat more of: Pick a plant, any plant!
Shah feels strongly that the more plants you enjoy, and the less meat you consume, the better your odds are for a long and healthy old age.
“The single dietary habit most consistently observed in individuals who age exceptionally well is long-term adherence to a predominantly plant-based, minimally processed dietary pattern,” he said.
#2 – Food to eat more of: Nuts, seeds and legumes!
Dr. Dariush Mozaffarian is a cardiologist, public health scientist and director of the Food is Medicine Institute at Tufts University. He says, as long as you’re not allergic to them, nuts and seeds are an incredibly healthful choice. “They’re remarkable life-giving packages of healthy fats, fibers, phenolics and other bioactives,” he said. “Gram for gram, nuts are one of the most potent foods out there, and they’re currently widely underconsumed by Americans.”
Shah agreed and included legumes (beans, lentils, peas and peanuts) as well, saying, “Based on current evidence, adding nuts and legumes to the diet may have the largest reduction in mortality based on the best studies we have.”
#3 – Food to eat more of: Protein.
“I’ve learned that protein is important for building muscle, and many of us, particularly women, don’t get enough,” said Dr. Lucinda A. Harris, a professor at the Mayo Clinic Alix School of Medicine. Some researchers in longevity and geriatric nutrition, including her, think that older adults need significantly more than the current RDA for protein of 0.8 grams per kilogram of body weight, and closer to 1.2 to 1.6 grams per kilogram. An example is a 150-pound person whose RDA is 54 grams of protein per day, but would need almost double that amount, about 109 grams of protein, to reach 1.6 grams per kilogram.
This matters because adequate protein plus exercise is needed to build muscle mass. “Building muscle helps prevent insulin resistance, which in turn helps prevent fatty liver, a current epidemic in this country, along with obesity,” Harris said.
#4 – Food to eat more of: Whole foods (hold the smoothies).
Dr. David Agus is a medical oncologist, CEO and founder of the Ellison Medical Institute, and author of “The Book of Animal Secrets: Nature’s Lessons for a Long and Happy Life.” He said that you should aim to chew more and sip less. “We were designed to chew food, and our GI system developed to absorb food, not shakes, smoothies or handfuls of supplements,” he said. “Once you start processing food, you get less benefit from it.” He simplified his message this way, saying: “We were made to eat oranges, not drink orange juice.”

#5 – Reminder: You deserve a little treat!
While she’s an advocate of eating less sugar in general, Harris offered this happy thought, stating: “A little bit of dark chocolate is still good.”
What these experts notice about their thriving older patients.
It turns out that those who work with older adults have plenty of anecdotal evidence about what the lifestyle of those they notice are doing best to age happily and healthily. What do those folks have in common? One factor is maintaining a “Goldilocks” weight — not too much and not too little. Shah said, “You need to achieve balance with a healthy weight. Beyond age 65, it can be as dangerous to be underweight as it is to be overweight.”
Other longevity factors were noted by Jenny Witherspoon, a registered dietitian specializing in aging services and oncology nutrition at the University of Oklahoma Health Sciences Center. She said there are a few key habits among those who do better in old age. “For one thing, they tend to eat mostly ‘actual food,’ not just food-like products,” she said. “I’ve noticed that movement is a normal part of their lifestyle, not an occasional reset. And they typically don’t drink alcohol.” She summed, saying, “The best agers aren’t perfect, but they’re consistent with real food, regular movement and little-to-no alcohol.”
Finally, consider these specific diets.
“The diets I recommend to my patients are the Mediterranean diet, the DASH diet and the MIND diet, which combines the two to optimize brain-health and reduce risk of dementia,” Shah said. “They can all be adapted to foods in any culture.”
Agus agreed, noting that in randomized studies, “the best results are found in the Mediterranean diet.” Harris also supports the Mediterranean diet, and says that those who follow it tend to eat less processed food, more fruits and vegetables and good fats like olive oil.
Finally, Witherspoon said that the best eating plan is one that’s realistic and sustainable. “It needs to be something a person can follow consistently, so choose an evidence-based eating pattern you can stick with, and pair it with exercise for the biggest payoff,” she said. “Start with the basics, focus on consistency and build a routine you can live with.”