Imagine you step on the scale one morning and find you've lost five pounds – without even trying...
At 35, you might celebrate. But if you're 75, it could signal one threat to healthy aging that gets surprisingly little attention.
You see, for most of our lives, we've been told to eat less and cut calories – whatever it takes to shed those extra pounds. But aging flips that script...
Our appetites might start shrinking... Dental problems can make eating uncomfortable... Medications can affect appetite or sense of taste... And mobility issues might make shopping or cooking harder.
Before you know it, you're not eating enough.
That's called undernutrition, which is a form of malnutrition. Malnutrition simply means that your body isn't getting the right amount of calories and nutrients.
Undernutrition happens when you're not getting enough energy, protein, or other nutrients to meet your body's needs.
It results in symptoms like weakness and fatigue, dry skin, and brittle hair or nails. And research shows it could also put your brain health at risk...
Eating Less Isn't Always Better
You don't necessarily have to look severely underweight to be undernourished...
In a 2024 study, European researchers analyzed 50 older adults at risk of poor nutrition and cognitive decline. Only 22% were meeting their recommended daily nutritional needs, and many weren't getting enough important vitamins and minerals... However, the average body-mass index was around 23.5, or right in the "normal" range.
Protein was another area of concern for these folks. Even though 82% met the U.K.'s daily recommendation of 0.75 grams of protein per kilogram of body weight – pretty much identical to the long-standing U.S. daily recommendation of 0.8 grams of protein per kilogram of body weight – only 34% consumed the higher target of 1.2 grams per kilogram each day.
That matters because as we age, we need even more protein to preserve muscle. That's key to maintaining our strength, mobility, and independence into our golden years.
And now, researchers are finding some interesting links between poor nutrition and the brain...
In a new study published in Nutrition, researchers followed 3,852 adults aged 65 to 96 for nine years. Participants who were undernourished at the start of the study had 71% higher odds of ending up in the group with the most rapid cognitive decline.
Of course, that doesn't necessarily mean undernutrition was the root cause... Worsening memory can also help cause undernutrition by making it harder to shop, cook, or even remember to eat.
But another recent study from the American Journal of Clinical Nutrition took things a step further. It involved 105 adults aged 68 on average who were at risk of undernutrition and cognitive decline.
One group received personalized advice for eating a protein-enriched Mediterranean diet. Another group followed the same diet and also engaged in a home exercise program. And a third group only got standard healthy-eating advice.
After six months, the first two groups improved their nutritional status. They also improved their scores on cognitive tests compared with the control group.
Now, this was a small, relatively short study and doesn't prove causation (that eating better prevents dementia). However, these studies do give us enough reason to avoid dismissing poor appetite and unintentional weight loss as normal parts of aging.
How to Fight Undernutrition
Here are a few practical tips to protect yourself or a loved one from undernutrition...
1. Pay attention to unexplained weight loss. It's one thing if you're deliberately trying to lose weight through diet and exercise. But if you're shedding pounds without putting in much effort – or if you're suddenly eating a lot less – tell your doctor. Don't automatically treat weight loss as a victory.
2. Eat "little and often." If you struggle to eat enough, try having smaller meals and snacks throughout the day instead of forcing yourself to down huge meals. Eating small meals makes it easier for your body to digest food, which means you'll avoid the pitfalls of fullness, indigestion, or bloating. I also recommend nutrient-dense snacks like a cup of Greek yogurt, a handful of nuts, some cheese, or fruit with nut butter.
3. Get some protein earlier in your day. In the first study I mentioned, researchers found that participants ate much less protein at breakfast and lunch compared with dinnertime. So if you're looking for ways to up your protein intake, do what I do... Make protein part of your morning routine. After all, your muscle protein synthesis drops overnight while your body is fasting. Eating breakfast helps your body switch from a breakdown state to a growth state.
The official U.S. recommendation might be 0.8 grams of protein per kilogram of body weight... but it turns out, we actually need more than that – especially as we age. And at least a third of U.S. adults aged 50 and older aren't getting enough protein. I explained all the details in the November 2025 issue of Retirement Millionaire – including my top tips for adding protein into your diet. (You can grab a trial subscription to my flagship newsletter here.)
As we age, we may need fewer calories than we did in our 30s. But that doesn't mean we need fewer nutrients. Remember... healthy eating isn't always about eating less. It's about making sure you're eating enough of the right foods.
What We're Reading...
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Here's to our health, wealth, and a great retirement,
Dr. David Eifrig and the Health & Wealth Bulletin Research Team
August 27, 2026