More Protein Is Not the Answer. Better Food Is.

After my last post on protein, I kept going down the rabbit hole. Protein is everywhere at the moment: bars, yoghurts, cereals, even water. The message on the packet is always the same. More is better.

Then I watched an interview with Christopher Gardner, a professor of medicine at Stanford who has spent around 30 years running large diet trials. He made a case that is a lot less exciting than the marketing. For me it was also a lot more useful.

Quick Answer: The body can't store extra protein. Once repair and maintenance are covered, the rest is broken down and burned or turned into other fuel. In Stanford's large DIETFITS trial, a healthy low-fat and a healthy low-carb diet gave almost the same average weight loss. What the successful diets had in common was quality: whole foods, vegetables and legumes, with little added sugar or refined grain.

01.Extra Protein Doesn't Get Stored

This was the part I didn't know. The body treats the three main nutrients very differently:

• Fat: it can store almost unlimited amounts.
• Carbohydrate: it keeps a small store in the liver and muscles. A marathon runner can use most of it in a few hours.
• Protein: there is no store at all.

Protein builds and repairs cells, enzymes and hormones. Whatever is left over is taken apart. The liver removes the nitrogen, the kidneys excrete it, and the rest is used for energy or turned into glucose or fat.

Gardner points out an irony for people on low-carb diets. Eggs for breakfast, steak for lunch and fish for dinner often add up to far more protein than the body can use, and part of that surplus becomes glucose: the very thing the diet was meant to avoid.

Protein still matters, of course. Beyond what you need, though, more doesn't add much. For most healthy adults, guidelines put that need at around 0.8 g per kilogram of body weight per day, with more often suggested for older adults and people who train hard. That matches what I found last time, and it's one reason I paused my daily scoop of protein powder.

02.Keto Was Never a High-Protein Diet

A lot of today's protein enthusiasm grew out of low-carb and keto. Gardner notes that the original ketogenic diet was developed decades ago to control seizures in children with epilepsy. It was around 70 to 80% fat with moderate protein, and it was a medical treatment.

The popular, meat-heavy version of keto is a different diet that happens to share the name. Gardner sees that pattern across nutrition: the label stays the same while the content changes.

This is where I had to smile, because the same applies to plant-based eating. Oreos, French fries and cola are technically vegan. I eat plant-based, and I'm very good at finding the unhealthy vegan options, white bread included. That is clearly not what people had in mind when they recommended whole grains, vegetables and legumes.

03.What a 609-Person Trial Found

Gardner's group ran one of the largest diet comparisons so far, the DIETFITS trial. 609 adults were randomly assigned to a healthy low-fat or a healthy low-carb diet for a year.

• Average weight loss was almost the same: 5.3 kg on low-fat and 6.0 kg on low-carb.
• The spread within each group was huge. According to Gardner, some people lost more than 25 kg while others gained around 9 kg, and the pattern looked the same for both diets.
• Genetic tests didn't predict who would succeed. A proposed "low-fat genotype" and "low-carb genotype" made no difference.
• Insulin response didn't predict it either.

The team had hoped to show which people should follow which diet, and they couldn't. What did stand out was that people who followed the healthy version of their diet did better than those who found ways around it with low-fat brownies or low-carb sweets. I recognise that trick.

The two diets did leave different marks in the blood. Low-fat lowered LDL cholesterol more. Low-carb lowered triglycerides more and raised HDL slightly. Blood sugar and insulin improved equally.

04.What Every Serious Diet Agrees On

Gardner also led an American Heart Association review of ten popular diet patterns, from Mediterranean and vegetarian to paleo and keto. For all the public arguing between their fans, they share four basics:

1. Eat more whole foods.
2. Eat more vegetables.
3. Eat less added sugar.
4. Eat less refined grain.

Number four is my white bread, so that one landed.

The patterns that fitted heart-health guidance best were Mediterranean, DASH, pescetarian and vegetarian. Keto and paleo came out weakest. Gardner adds six foods with broad expert support: beans, peas and lentils; whole fruit; nuts and seeds; fish; eggs; and plain yoghurt. As someone who mostly eats plant-based but has the odd piece of fish or some kefir, I found that list reassuring.

05.Fibre Is the Better Target

If you want to optimise something, Gardner suggests fibre instead of protein. Most people in Western countries eat far too little of it.

Beans, peas and lentils are the obvious place to start. They bring protein and fibre at the same time, they're cheap, and almost every serious diet recommends them. A bowl of lentils does more for a typical diet than another protein bar, and it's a much easier habit for me to build than counting grams.

06.Seed Oils and "Inflammation"

The interview also covers the campaign against seed oils such as sunflower and canola. Gardner is direct: decades of trials show that replacing butter, lard or beef tallow with these oils lowers LDL cholesterol.

His explanation for the backlash is that most seed oil today is eaten in ultra-processed food. The trouble lies with the crisps and fried snacks, and much less with the oil in a home-made salad dressing.

He made one more point I'll remember. "Inflammation" gets blamed for a lot, but apart from CRP there is no agreed clinical test for chronic inflammation and no accepted normal range. So claims that a particular food "causes inflammation" are very hard to prove or disprove.

07.What I'm Taking From This

1. Less counting of protein. I'll make sure I get enough from whole foods and stop chasing numbers.
2. More beans, lentils and peas. They're my easiest way to get both protein and fibre.
3. Less white bread, again. Wholegrain or sourdough where I can.
4. Reading the food, and ignoring the claim on the packet. "High protein", "low fat" and "low carb" say little about quality.
5. Two questions before cutting anything out: what am I eating it with, and what would replace it?

Gardner closed the interview by quoting Michael Pollan's seven words from 2006, a little reluctantly after 90 minutes of science: "Eat food. Not too much. Mostly plants."

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Sources

• Interview: "I've Studied Nutrition At Stanford For 30 Years… You're Eating Too Much Protein", Christopher Gardner with Sean Kim (YouTube), 11 September 2026.
• Gardner CD, et al. Effect of low-fat vs low-carbohydrate diet on 12-month weight loss in overweight adults (the DIETFITS randomized clinical trial). JAMA, 2018. doi:10.1001/jama.2018.0245 (via PubMed)
• Gardner CD, et al. Popular dietary patterns: alignment with American Heart Association 2021 dietary guidance. Circulation, 2023. doi:10.1161/CIR.0000000000001146 (via PubMed)