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Today’s Health Upgrade
Examining the dangers of high-protein diets
Why some snacks make you hungrier
Mentally exhausted? Try this brain jumpstart
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Health
Are High-Protein Diets Dangerous? Here’s What the Science Actually Says
If you’ve ever worried that eating too much protein might harm your kidneys, bones, or longevity, you’re not alone. These claims have floated around for decades. But are they true?
Scientists found there’s no strong evidence that high-protein diets cause harm in healthy individuals, and most common concerns are based on outdated, flawed, or misinterpreted research.
That was the takeaway from a comprehensive review of 60 years of evidence. Researchers dug into the most common claims about high-protein diets, including potential damage to kidneys, bones, liver function, cancer risk, and overall mortality.
When you break down the studies, most of the criticisms of protein come from animal studies that don’t translate to humans, research without actual health outcomes (like assuming more urea = worse kidney health), studies that confuse correlation with causation, or a failure to account for important lifestyle confounders (like smoking, activity, or fiber intake).
Take kidney damage, for example. Many believe high protein intake overworks your kidneys. But in healthy people, numerous clinical trials show no signs of declining kidney function, even with intakes well above the RDA.
The same goes for claims about calcium loss and bone health—research actually shows higher protein intakes support better bone density, especially when calcium intake is adequate.
When it comes to longevity, some observational studies have linked high protein intake to increased mortality, but the signal disappears (or reverses) when you look at high-quality protein sources or adjust for confounding factors. In fact, restricting protein may do more harm than good, especially in aging adults who need it to maintain muscle and independence.
The review concludes that it’s implausible that high-protein diets independently increase mortality risk in healthy people.
If you’re active, trying to build or maintain muscle, or just want to age well, eating more protein is likely beneficial—not harmful. Aim for high-quality sources, such as eggs, dairy, meat, fish, or plants like legumes and soy, and don’t fear the extra grams. Instead of worrying about protein being “too high,” it's better to ask whether you’re getting enough for your goals and lifestyle.
Together With David
Why Some Snacks Make You Hungrier
You’re not imagining it: some “healthy” snacks leave you wanting more food than before you started eating.
That’s because most snacks are high-energy-density foods, meaning they pack a lot of calories into a small volume. In reality, you want the opposite.
Research found that low-energy-density foods not only help control hunger but also lead to lower calorie intake and more effective fat loss. Why? Because you feel full on fewer calories without even trying.
Scientists analyzed the diets of more than 7,000 adults to investigate how energy density (calories per gram of food) influences daily energy intake and body weight.
Those who ate low-energy-dense diets consumed anywhere from 275 to 425 fewer calories per day than those with high-energy-dense diets.
And here’s the twist: both groups who ate fewer calories ate more food — about 400 grams more for men and 300 grams more for women (roughly one extra pound of food).
Those eating lower-energy-dense diets (think fruits, vegetables, lean proteins, and broth-based soups) had the lowest obesity rates. Meanwhile, higher dietary energy density was directly associated with higher body weight.
Foods with fewer calories per gram fill your stomach and trigger feelings of fullness — a major driver of appetite. This makes it easier to stop eating when you’re satisfied rather than stuffed.
Snacking smarter isn’t about eating less food—it’s about eating the right kind.
That’s the secret most protein bars miss. They promise nutrition, but deliver the type of calories that don’t leave you satisfied. Most protein bars are more candy bar than nutrient powerhouse: 200+ calories, 10g of sugar, and a protein blend that’s incomplete or poorly absorbed.
If you want a protein bar that’s more pure protein — and less of everything else — David is different. It packs in 28 grams of protein in only 150 calories, and doesn’t add any sugar to your diet.
It’s the highest protein-per-calorie ratio we’ve seen in any snack — technically.
If you wanted fewer calories and more protein, you could always eat boiled cod. It’s loaded with 23 grams of protein, 100 calories, and is also sugar-free.
And if that’s your style, David is determined to give you the best protein options in the world, as they are now offering frozen cod to anyone who wants fish on the go (yep, they’re serious).
It’s everything you need to support fat loss and muscle gain—without spiking your blood sugar or sneaking in unwanted calories.
So whether you want a sweet indulgence like chocolate chip cookie dough, red velvet, cinnamon roll — or a timeless bodybuilding staple like cod — David now has you covered for all your protein needs.
You can subscribe and save 10 percent on the bars, or buy 4 boxes and get 1 free. Thawing and cooking of the cod is sold separately. Thawing and cooking of the cod is sold separately.
Instant Health Boost
When You’re Mentally Fried, Try This
Ever feel like your brain’s running on empty by mid-afternoon? Science suggests there’s a quick, calm, free way to reboot your mind.
Looking at pictures of nature can almost immediately improve attention and reduce mental fatigue.
Multiple studies have examined the seemingly magical restorative powers of the outdoors. In two experiments, participants either walked in a natural setting, an urban area, or simply viewed pictures of nature. In all scenarios, exposure to nature improved attention, working memory, and mental fatigue.
Nature wasn’t just a mood booster—it made people smarter in the moment.
The researchers believe nature provides the perfect balance of stimulation and rest. It activates your senses enough to keep you engaged but not so much that it overwhelms your ability to concentrate. This allows your top-down attention systems—your brain’s executive control center—to recharge.
And before you think, “I can’t get outdoors,” studies have found that you don’t need to be in nature to experience its benefits.
It turns out that even brief virtual exposure to forests, mountains, or oceans can replicate some of the attention-restoring benefits you’d get from being in nature—without leaving your desk. In one study, as little as 6 minutes improved attention.
So the next time your focus fades or your brain feels like it’s slogging through mud, take a pause and get outdoors or search for a serene forest, a quiet beach, or a sunlit meadow on your phone, and soak it in. You’ll return to your work with sharper focus—and a calmer mind.
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Publisher: Arnold Schwarzenegger
Editors-in-chief: Adam Bornstein and Daniel Ketchell
