En español | It was 1941. The National Academy of Sciences, tasked with helping out World War II food-relief efforts, issued a report that addressed this question: What nutrients, and in what amounts, do people need to be healthy?
The government's food experts weren't thinking about long-term health issues such as diabetes or heart disease. They were more concerned about an adequately fed population that was free from scurvy, rickets and other wartime diseases of malnutrition. And the numbers they landed on for protein, calories, six vitamins and two minerals were dubbed the recommended dietary allowances (RDAs). It may surprise you to learn that the RDAs are still driving dietary advice today. They underpin every nutritional label on every package in your pantry, and they're used to establish eating plans for everyone from schoolchildren to nursing home residents. And while, yes, the guidelines for preventing nutritional deficiencies and promoting health have been adjusted over the decades, they're still building toward long-term health goals like preventing chronic disease.
"We know that certain nutrients are better in higher amounts,” says Katherine Tucker, director of the Center for Population Health at the University of Massachusetts Lowell. “It's not just about preventing deficiency diseases. It's about keeping our systems optimal as we age."
Although the past six months have sure had echoes of wartime deprivation — with depleted grocery shelves for certain items — Americans haven't been at any real risk of developing scurvy. With fall harvest season ahead, it's a good time to reassess what your body needs now, for maximum health in this decade and the decades to come.
To head off diabetes: Optimize your hormone balance
Insulin is critical to healthy aging. It's the hormone that moves sugar from your bloodstream into your muscle, fat and liver cells. But when your blood sugar is consistently high — which is often the result of a sweet and refined-carbohydrate diet — your muscle, fat and liver cells stop responding well to insulin. Doctors call this insulin resistance, and it explains why about 1 in 10 American adults have type 2 diabetes.
While losing weight is crucial to keeping your insulin responsive, so too is minimizing blood-sugar spikes. In addition to avoiding sweet and refined-carbohydrate foods, the way to stabilize blood sugar is by adding more fiber to your diet. One type of fiber to be aware of is insoluble fiber. It's the nondigestible kind; you might have referred to it as roughage. It passes through the upper gut undigested, to feed the good bacteria in the lower intestines. “These bacteria are little factories that produce chemicals that affect our hormone balance,” Tucker explains. The combo of roughage and good bacteria offers a double hit of diabetes protection: The roughage slows digestion (and blood sugar), while the bacteria help to improve your insulin sensitivity.
How much fiber is enough? The RDAs advise that women over 50 eat 21 grams a day; for men, the goal is 30 grams. And this is a case where the specific targets matter: National consumption surveys indicate that only about 5 percent of people consume their daily fiber quota, yet doing so can reduce your risk of developing type 2 diabetes by as much as 20 to 30 percent, according to a study published in the Journal of Nutrition. “Almost no adult eats enough fiber,” says Kathleen Niedert, a health care administrator, registered dietitian and author of Nutrition Care of the Older Adult. “And it's difficult to get what you need unless you start your day with bran cereal.”
To her point, 1/4 cup of bran delivers 6 grams of insoluble fiber — that's about 25 percent of your entire day's needs. Try sprinkling it over oatmeal or blending it into smoothies or casseroles. Generally speaking, fruits and vegetables are good sources of fiber, too. But to max your intake of the insoluble stuff, replace your refined grains and white bread with whole-grain everything. A cup of cooked white rice has about 0.6 grams of fiber; brown rice, however, has 3.5 grams, while barley delivers about 6 grams of mostly insoluble fiber.
To stop muscle loss: Have one or more protein sources every meal
Age-related muscle deterioration kicks into high gear around age 50, notes Rosilene Ribeiro, a nutritional epidemiologist at the University of Sydney. Even if you're not an aspiring bodybuilder, that's a problem. “Muscle mass is linked with everyday functionality,” Ribeiro says. “It affects normal things like gardening and walking long distances.”
Worse, muscle loss can be hard to notice. In a study of nearly 1,900 older adults, researchers from the University of Pittsburgh determined that you're losing strength about three times faster than muscle mass. So, though your biceps might stay the same size, the quality of the muscle is withering. If you don't eat for strength now, you might one day struggle to mow your own lawn or lift a bag of potting soil. “When you can no longer do things you once could, it creates a snowball effect,” Ribeiro observes.
But you don't have to let your muscles go to mush. Resistance training — weightlifting, yoga or Pilates — is the main way to stay strong. It also helps to double down on dietary protein. The government recommends 0.8 grams of daily protein per kilogram of body weight, which is about 65 grams for a 180-pound person. But that recommendation doesn't account for age. It's the same for a 50-year-old as it is for a 20-year-old, who can basically build muscle by operating a TV remote.
"We know that older adults need proportionately more protein in their diets than they do when they're younger,” says Christine Ritchie, director of research for the division of palliative care and geriatric medicine at Massachusetts General Hospital and a professor of medicine at Harvard Medical School. “So, I generally encourage older people to increase their protein to a range of 1 gram to no more than 2 grams of protein per kilogram of body weight.” After conversion, that means a 180-pound man in his 50s should aim for 82 to 164 grams per day. Better yet, just plan on eating about 25 to 30 grams at each meal (that's about a medium chicken breast or burger, a 5-ounce can of tuna mixed with mayo, 2 cups of cooked rice and beans, or a cup of low-fat cottage cheese). “Ingesting protein multiple times throughout the day is going to be a lot more effective than having one big steak at the end of the day,” Ritchie adds.
Animal proteins provide the richest array of amino acids, which are the building blocks you need to boost muscle, but multiple plant sources combined in one meal can be just as good, Ribeiro says. In addition to eating eggs, meat, dairy and fish, consider increasing your protein intake with chickpeas, lentils, tofu and quinoa.
To avoid weight gain: Remember the 200-calorie rule
The number of calories you need each day drops slightly as you age, yet most people keep eating the same amount of food. The government's dietary guidelines advise that you burn approximately 200 fewer daily calories after age 50. So, if you're a 50-year-old who eats like a 40-year-old, you could gain more than a pound of body fat each month. “It's simple, really,” says Nancy Rodriguez, a professor of nutritional sciences at the University of Connecticut. “If your calorie burn goes down and you don't change the way you eat, then you're going to put on weight."
Of course, unless you suddenly take up marathon running, exercise alone won't restore the calorie burn of youth. That's because roughly 50 to 70 percent of the energy you burn each day goes toward sustaining the body: organ function, respiration and the other processes that keep you alive. Nutritionists call this your basal metabolic rate, and it's the slowdown of this rate — not your lapsed gym membership — that's the main reason you need fewer calories with age.
Although creeping weight gain may be normal, that doesn't make it healthy. So what number should you look for on the scale? Think more about your waistline: A waist circumference of greater than 40 inches for men, or 35 inches for women, puts you at greater risk for disease. To get, and remain, below those numbers, you have to cut a few calories — start with 200 — from your daily diet. Yet rather than concentrating on eating less, think about eating better, especially when snacking. If you can answer your cravings with hunger-satisfying protein and belly-filling fiber, you can cut calories without thinking about it.
"An Oreo has roughly the same number of calories as a small apple,” says Niedert. “But while it's easy to eat six Oreos, how many people could eat six apples?”
Fruit is, of course, a healthy snack. So are nuts, raw vegetables and unsweetened yogurt. All these filling foods provide you with fiber and/or protein while injecting an army of disease-fighting, brain-protecting nutrients into your bloodstream. “The big challenge for older adults is that they need less energy overall but more micronutrients,” Tucker says, “which means you need a greater focus on nutrient-dense foods.”
So try to pack as many fruits and vegetables into your day as possible, and limit (or even better, eliminate!) nutritionally bankrupt doughnuts, cookies and candy. By using each snack craving as an opportunity to add nutrients into your diet, you'll slim down without having to obsess about calories.
To build bone strength: Hit the dairy bar daily
For most people, bone mass reaches its zenith in the late 20s and then begins a decades-long process of bone loss. For some 10 million Americans, that eventually results in osteoporosis, a condition marked by weak bones and an increased risk of injury. “Fractures are a huge problem in the elderly,” Ribeiro notes. “With age, both hospital recovery time and the health issues related to recovery go way up."
If you're not already eating to protect your bones, now is the time to begin. You can do that by making sure you're getting adequate amounts of calcium and its best pal, vitamin D. (Your body stores vitamin D in fat tissue, to help with calcium absorption as needed.) In one study of adults 50 and older, all of whom had recently fractured bones, 43 percent were deficient in both calcium and vitamin D.
For calcium, aim to hit the American Academy of Orthopaedic Surgeons’ recommendation of 1,200 milligrams a day if you're a woman and 1,000 mg if you're a man. Those numbers are only slightly less than the ones provided to growing teenagers, and you'll get most of the way there with a couple of slices of cheese in your sandwich (300 mg), an afternoon yogurt snack (200 mg in a 6-ounce cup) and a scoop of low-fat cottage cheese with dinner (125 mg). “If people do the three-a-day thing for dairy, they'll hit their calcium quota,” Rodriguez says. She recommends sticking to food sources over supplements, if possible, since the excessive calcium levels in pills can turn into arterial plaque. (In a review published last year of more than 1,200 studies, researchers determined that calcium supplements were associated with a 14 percent jump in the risk for a heart attack.) In addition to eating dairy foods, choosing leafy greens, broccoli, beans and almonds will help you achieve your calcium goals. And for vitamin D, the best food sources include egg yolks, milk fortified with vitamin D, and fatty fish (think salmon, tuna and mackerel). And be sure to take in a daily dose of sunlight, since your body creates this vitamin naturally when the sun's energy reacts with a form of cholesterol in your skin.
To reduce chronic inflammation: Check out labels
When your immune system was young, it zapped health threats with surgical precision. But with time, immune systems can start overreacting to small threats, or attacking things that don't pose any threat at all. That out-of-control immune response is known as chronic inflammation, and it can cause damage throughout your body. Initially you might feel this as stiffness or achy joints, but in time, it can result in much bigger problems. “The inflammation that's causing discomfort is the same inflammation that happens in your brain cells and leads to dementia,” says Hal Blatman, M.D., a pain specialist in Cincinnati. “It's all part of the same fire that needs to be put out.”
Chronic inflammation can cause arthritis, heart disease and depression. And it's so common among older people that researchers have begun calling it inflammaging. The best way to tackle the problem, Blatman advises, is to eliminate sugar from your diet. In studies, mice fed high-carbohydrate, high-fat diets don't generally show significant inflammatory responses until sugar is added into the mix. And according to a study of 6,856 subjects published this year in the International Journal of Public Health, people who drank the most sugar-sweetened beverages had higher levels of C-reactive protein, a substance the liver produces in response to inflammation.
"Any time you raise the insulin level in your body” — a natural response to sugar and starchy foods — “you're going to see an increase in body-wide inflammation,” Blatman says.
Thankfully, new governmental regulations are making it easier to identify hidden sources of caloric sweeteners. Starting this year, every big food company must list “Added Sugars” on its Nutrition Facts labeling. So, when a seemingly safe jar of marinara sauce or bottle of salad dressing contains unnecessary grams of added sugar (check — many of them do!), you'll know it at a glance.
To further stifle inflammation, Blatman also recommends cutting out refined flour and hydrogenated fats: “If you eliminate all inflammatory foods, half your pain will go away in two to 12 weeks."
To keep your arteries supple: Look beyond the beige
As it turns out, natural hues such as blue, yellow and red in your food generally indicate higher levels of heart-protecting antioxidants. “Your diet needs to be colorful,” Niedert says. “The more colors you have, the better off you are.”
Take berries. In a randomized, double-blind study of 115 adults 50 and older, published last year in the American Journal of Clinical Nutrition, those who committed to eating 1 cup of blueberries every day for six months showed improved vascular function and higher levels of heart-healthy HDL cholesterol. The study's authors credit a deeply colored antioxidant called anthocyanin, which is also found in cherries, raspberries and blackberries.
Betalain is another powerful pigment. It's responsible for making beets red, and a study that appeared last year in the journal Food & Function discovered that it could help those with coronary artery disease improve their heart health by lowering bad LDL cholesterol and skimming out homocysteine, an amino acid that can damage the lining of arteries and increase the risk of blood clots.
The truth is, you'd be hard-pressed to find a colorful fruit or vegetable that doesn't offer some kind of heart-protecting benefit. Lycopene (the red pigment in tomatoes) and beta-carotene (which turns carrots orange) have both proved to be cardiovascular heroes. Plus, in a 2016 study, 200 mg doses of curcumin, the compound that gives turmeric its sun-colored glow, was shown to increase the vascular functioning of blood vessels by 3 percent. (A more recent study found the effect to be even more dramatic immediately following a workout.)
The point here is that if your plate is a sea of beige — the lifeless color of fried chicken, fries and dinner rolls — you're doing your heart a disservice. Research continues to support what dietitians such as Niedert have long preached: By eating brightly colored bell peppers, purple cabbage and yellow squash, you can keep your ticker strong.
And, no, artificial coloring doesn't count. Sorry, Froot Loops.
A perfect day of eating in your 50s
Who says a healthy diet has to be complicated? This menu combines simple whole foods to make meals you already know how to prepare, yet it delivers all the protein, fiber and plant-based nutrients that can help you ward off disease and keep your metabolism revved.
Breakfast: 3-egg vegetable omelet topped with a big dollop of Greek yogurt; glass of 2 percent milk
Cup of low-fat cottage cheese with mixed fruit and toast with avocado
Protein shake (at least 25 grams of protein per serving) and melon slice
Midmorning snack: Apple or similar-sized piece of fruit
Lunch: Chicken-and-vegetable stir-fry with chickpeas, served over barley
Burrito bowl with chicken, black beans, brown rice, guacamole, cheese, lettuce and salsa
Afternoon snack: Cheese slices, whole-grain crackers and blueberries
Dinner: 6-ounce salmon fillet with quinoa and vegetables
Salad with lettuce, mixed vegetables (carrots, cucumber, tomato, sweet potato), 4 ounces of grilled fish, chicken or seitan, topped with extra-virgin olive oil and vinegar dressing
Nutritional impact: 1,540–1,920 calories; 99–145 grams protein; 26-34 grams fiber
A perfect day of eating in your 60s and 70s
Breakfast: 3-egg vegetable omelet topped with a large dollop of Greek yogurt; glass of 2 percent milk
Midmorning snack: Apple or similar-sized piece of fruit
Lunch: Chicken-and-vegetable stir-fry with chickpeas, served over barley
Afternoon snack: Cottage cheese topped with blueberries and mixed nuts
Dinner: 6-ounce salmon fillet served with black beans and vegetables
Nutritional values: 1,840 calories, 140 grams protein, 39 grams fiber