Health Library / Lifestyle
This content is for education only and is not medical advice. I'm a fitness coach, not a physician. Talk to your doctor before starting any medication, hormone, supplement, or new exercise program, especially if you have a medical condition or take prescriptions.
Thirty years of public argument, two tribes, enormous quantities of book sales, and the honest answer is boring.
When researchers take people, match their calories and their protein, and put one group on low carb and the other on low fat — the results come out remarkably similar. Not identical for every individual, but nothing like the gap either side promised.
So the answer to "carbs or fat?" is mostly: whichever one you can actually live on. Adherence beats the ratio. That's the finding, and neither camp wanted it.
What that frees you to do is think about the parts that do matter.
The protein module is the one with the real target, because the requirement genuinely rises with age and most people are well under it.
Once protein is handled, carbs and fat are splitting what's left. That's a preference and a lifestyle question far more than a physiology one.
Training. This is the clearest case. Carbohydrate is the fuel for hard work. Glycogen — stored carbohydrate in muscle — is what powers a heavy set and the last interval. Train low on carbs and your session quality drops.
People who go very low carb and then can't understand why their lifts stalled are usually looking at that. If you're lifting seriously two to four times a week, some carbohydrate around training earns its keep.
Fibre, which almost only comes with carbohydrate foods, and which most people are getting about half of. See the gut module — this is the single biggest dietary gap in the country.
Sleep and mood, for some people. Very low carb makes a portion of people sleep badly and feel flat. If that's you, that's data, not weakness.
The distinction that matters is not carbs versus no carbs. It's whole versus refined. Potatoes, oats, rice, beans, fruit come with fibre, water and micronutrients. A pastry doesn't. Treating those as the same category because they share a macronutrient is how the whole argument went wrong.
It's essential. Hormone production, cell membranes, absorbing vitamins A, D, E and K. Very low fat is its own mistake.
Satiety and food quality. Fat makes food worth eating, and a diet you resent doesn't survive.
Omega-3s, from fatty fish, which most people don't eat enough of.
On saturated fat, I'll be straight: this is genuinely less settled than it was presented in either direction. The confident "it's fine now" takes are as overstated as the old "it's poison" ones. Mainstream guidance still favours moderating it and favouring unsaturated sources, and that's a reasonable default while the argument continues.
Trans fats are the one with no defenders left. Largely gone from the food supply and good riddance.
Anchor the protein. Fill most of the rest with whole foods, plants, and fibre. Put more of your carbs around the days you train hard. Keep fat mostly from fish, olive oil, nuts and avocado rather than from fried and packaged things. Notice which ratio makes you feel and train better, and use that one.
That is genuinely most of it. The rest is detail that matters far less than whether you keep doing it for a decade.
If you have diabetes or prediabetes, carbohydrate is part of your medical management and the numbers come from your doctor or a dietitian, not from me or a book. Same for kidney disease, heart conditions under dietary management, and anything where food is part of the treatment.
The general principles above still apply to you. The specific targets don't come from a coach.
There is no macronutrient villain. There's a protein floor most people miss, a fibre gap most people have, and an enormous amount of energy spent arguing about the split that would have been better spent on either.
Last updated September 30, 2026