For the last two years I’ve been working on Ikaria, a service that continuously optimizes your diet to put your health and performance goals on autopilot. As a result I’ve gone way, way down the rabbit hole on just about every diet and every nutrition fad you’ve heard of.
I’ve read countless books and research articles, listened to hundreds of podcasts and interviews, and analyzed everything from packaging materials to protein powders to find ground truth on all the noise.
So: What works? What doesn’t? What’s real and what’s just marketing hype? Why can some people stick to diets and others can’t? What actually matters?
1. Eat real food. Processed food is making you fat.
If you take only one thing away from reading this post, it should be this. Stop eating ultra-processed food. Eat real food.
What’s ultra-processed food? On a high level, you can think of it this way: if you look at the ingredients list for something you’re about to eat and there are things on it you wouldn’t find in your home kitchen, it counts as ultra-processed food (UPF). Banana? Not UPF. Oreo? UPF. McDonald’s hamburger? Absolutely UPF.
Ultra-processed food is generally (but not always) manufactured, packaged, and branded. The American food system is massively tilted towards ultra-processed food. Why? A whole book could be written about this (and has — if you’re interested, go read “Ultra-Processed People” by Chris van Tulleken), but the short version is:
- It’s cheaper and more predictable to manufacture at scale, creating a more uniform product (which consumers like)
- It’s cheaper and easier to transport (more tolerant of heat and cold, stays fresh longer)
- It lasts longer on shelves
- It can be precisely engineered (tweaking salt, sugar, and fat content) to create a product people crave
If you’re a food company, your goal is to make as much money as possible. It’s not to make people healthy (though you can certainly sell that vision to consumers). It’s making and selling a product that people want to buy. So: keep your costs (manufacture, transport, spoilage) low and maximize your revenue and repeat buying.
I’m not going to be polemic and say food companies want you to get fat or be unhealthy. That’s putting too much sinister motive behind their behavior. They’re just responding to incentives. Food companies are indifferent to health outcomes because whether you’re healthy or unhealthy doesn’t really affect their economics. They just want to make a product that consumers buy repeatedly. That’s all. It’s no different from companies that make toilet paper or cell phones or t-shirts.
The act of processing food to this degree — separating it into its constituent parts and recombining it to make cookies or fruit snacks or even a hamburger — significantly alters its nutritional properties and the chemical impact it has on your body. While your taste buds might say, “I’m eating a hamburger,” the nutrition received by your stomach from a UPF hamburger falls short of that — fewer nutrients, less fiber, etc. — so your brain doesn’t receive the same neurochemical satiation signals from the gut and doesn’t turn off your hunger. As a result, you respond by eating more. You won’t be doubling what you eat but it’s enough of a difference that if it’s added up over days, months, and years, it will absolutely affect your waistline. Ultra-processed foods trick your body into eating more calories than it needs.
Eating real food is difficult. It’s more expensive, it’s more work (because it spoils more easily), and the flavors, to a palate habituated to ultra-processed food, are less exciting. But once your taste buds acclimate to less intense flavors, ultra-processed foods will taste synthetic and garish, a fun-house mirror version of the foods they’re intended to replace.
I’ve been eating this way — real food — for the last 3 years and I’ve never been in better health. My biomarkers have improved, I’m sub-8% body fat, and I feel great. I also spend a lot more time and money on my food than I used to.
That’s the trade-off: convenience and affordability on the side of ultra-processed foods vs. your health on the other. It’s really no more complicated than that.
2. For short-term results, fad diets (keto, paleo, intermittent fasting, Whole30, etc.) are essentially interchangeable
Most fad diets work the same way: by limiting your calories. It doesn’t matter whether it’s keto, paleo, Whole30, or intermittent fasting.
If you only allow yourself to eat in a 4 hour window every day, you will eat fewer calories.
If you don’t allow yourself to eat carbs, you will eat fewer calories.
If you cut out all dairy, gluten, and seed oils, you will eat fewer calories.
My first job out of college was working on Wall Street at an investment bank. I worked over 100 hours a week repeatedly and slept an average of 4–5 hours a night. A lot of my colleagues gained weight during that time. In fact, it’s common for people who sleep less to weigh more, and not just because of the impact of sleep deprivation on stress hormones. It’s because if you’re awake longer, you have more conscious hours during which you can eat. So you eat more.
For short-term results, it’s really as simple as restricting calorie intake. All of these diets accomplish that because they restrict what you’re allowed to eat, so people respond by eating less. So why would you choose one diet over another? Well…
3. The biggest determining factor for whether a diet delivers results is whether you can stick to it
Does intermittent fasting take a ton of willpower and turn you into a rage monster from the hunger? Ditch it. Does cutting out carbs completely leave you brain-dead, miserable, and unable to summon the energy to go to the gym? Maybe don’t do that. A “perfect” diet you can’t sustain is inferior to one that’s 80% as good but gets 100% compliance.
Diet results don’t come in 1 week or even 1 month. It’s about building habits that you can maintain for months and years. Health is a lifestyle: there’s never a point at which you stop thinking about it one way or another. So make it something you can sustain rather than something that drives you crazy.
4. What you eat to look good and what you eat to be healthy are not the same
This may sound obvious, but it needs to be said. To take this to its logical conclusion: for every Jack LaLanne there’s a dozen bodybuilders who died in their 30s, 40s, or 50s from cardiac issues brought on by steroid abuse. But you don’t even have to go as far as competitive bodybuilding to get the point that “better” physique can harm health.
Looking good is mostly about hitting a specific ratio of muscle vs. body fat, but being healthy isn’t necessarily visible to the eye. Sure, we look at Jeff Bezos’s biceps and think “dude’s in great shape” (which he is) but we have no idea what his cholesterol levels or coronary calcium score are.
There’s obviously a well-documented correlation between obesity and heart disease. But just because “too much body fat = unhealthy” doesn’t mean that minimizing body fat maximizes health. The things you need to do to absolutely minimize body fat are bad for your liver, kidneys, and heart. You can get ripped (or toned) while eating bacon and red meat, but both of those are incontrovertibly bad for long-term health. (And anyone who tells you otherwise is trying to sell you something.)
While there’s intriguing early research ongoing exploring the long-term health benefits of several recent diet trends (e.g. caloric restriction and longevity, ketosis and neuroprotection), many of the methods being touted by fitness influencers on Instagram at best are no better than your current diet, and at worst are actively harmful. (I’m looking at you, Liver King.)
There’s a decent amount of research that tells us that a Mediterranean diet is generally good for long-term health. Will it help you get a six pack by summer? Maybe or maybe not, but anything that purports to work that rapidly involves serious trade-offs. Is Whole30 a better choice in the long run? There’s not much research on that, but either is going to be miles better than a standard American diet full of ultra-processed food.
Obviously everyone wants to look good and be healthy. Just beware that there can be trade-offs between aesthetics and health and make those decisions consciously.
5. People get distracted by micro-optimizations and forget the big picture
There’s no shortage of direct-to-consumer companies touting the benefits of whatever pill or molecule du jour that will supposedly help you build muscle, burn fat, eliminate brain fog, improve your hair and nails, increase your energy (whatever that means), or help you achieve any of a number of far-fetched but desirable outcomes. There are thousands of fitness influencers telling you about the 7 workouts you need to do for killer abs or strong shoulders or to get rid of that pesky arm waddle. Almost everywhere you turn someone is doing a cold plunge or an infrared sauna or cryo to help with workout recovery.
The reality is: for most people none of this makes an appreciable difference. They’re optimizations that will get an additional 1% of performance. If you’re a world-class athlete, 1% is the difference between a gold medal and middle of the pack. But most of the rest of us aren’t consistently doing the basics, so focusing on these specific tools and techniques won’t change the outcomes. However, they make for compelling content that makes people think they know a secret to elite performance, so it plays well on social media.
If you’re not already sleeping 7–8 hours a night, eating only real food, getting 10k steps a day, and doing full-body weight training 4+ times a week, and doing so week-in, week-out for at least 4–6 months, no pill or powder will change your results.
If those pills and powders keep you motivated: great! Use them. They can be the magic feather that keeps you going so you make progress. But the progress comes from consistently doing the boring stuff, not because your hydrolyzed collagen powder comes from organic shade-grown albino free-range wild-caught Atlantic whitefish.
DNA-based diets? Bogus. Supplements personalized by your biomarkers? Marginal at best. (Biomarkers are complex, interdependent, their interpretation depends on qualitative factors, and we can’t yet deterministically move them either.)
Sleep. Eat real food. Move. Lift weights. Repeat every day for 6 months. Do whatever it takes to get the basics down consistently. Results will follow.
6. Most people who want to look “toned” are better served gaining muscle rather than losing weight
This may sound counter-intuitive, but there are a few reasons this is the case. And now, with the advent of weight loss drugs like Ozempic, this is more important than ever. It’s becoming much easier to lose those last few pounds, but the problem was never actually the body fat — it was the lack of muscle.
First: if you have more muscle, your basal metabolic rate is higher. Your body needs more calories just to sustain your muscles. This means you can eat more calories while still maintaining a caloric deficit and losing weight. Once you add muscle, it becomes easier to lose weight because your body needs more calories just to maintain itself.
Second: it’s quite hard to actually gain muscle. Even with the benefit of testosterone, many men struggle to put on muscle. So if you focus your workouts on building muscle rather than “burning fat” you’re likely to do both. Weight lifting — which most people associate with building muscle — is very calorically demanding, almost as much as cardio. And it has the added bonus — unlike cardio — of being quite effective at triggering muscle growth. So at worst you’ll maintain your muscles while still losing weight, compared to a cardio-focused program (which can also lead to metabolic adaptation, meaning you have to work out harder to get the same results because your body learns to be more efficient at utilizing calories to do work).
Third: muscle is what gives your body shape. If you take someone who’s “skinny-fat” and remove the fat, you don’t get someone who’s toned; you get someone who’s skinny. People in this category who take Ozempic end up looking skeletal, not healthy. The reason they weren’t toned was never the fat on their body: it was their lack of muscle.
Aesthetics are always subjective, but if you’re thinking to yourself that you wish you looked more “toned”, consider reorienting your approach to focus on building muscle before worrying about burning fat.
None of these “secrets” is actually a secret. Most people reading this already know most of this information deep down inside. Just know that even if you spend years poring over research and case studies and everything bit of performance health and nutrition information you can get your hands on, the big conclusions are the same. There’s no hidden trick. There’s nothing being kept from you. You already have all the information you need. What you do with it is up to you.