Healthy mostly means you get all the stuff you need and not too much of anything.
So what you need and what you need to avoid depends on your body and environment.

You can try to keep book of all the essential vitamins and minerals in your diet.
Or you research what the body needs and what the commonly acknowledged limits are. Then you can just supplement them in reasonable quantities to make it highly unlikely to be deficient or overdosed in any of them. And that's what I do.
always be careful to not overdose Potassium, Iodine, or Calcium. Don't supplement vitamin A. Get β-carotene instead as the body makes vitamin A from it as needed.

Chances are, you get enough protein because it's really hard not to in an industrialized nation.
But it might be worth to look at the different amino acids and the overall protein intake if you don't like meat, tofu, or highly processed meat replacements.

If you really don't eat any fish or mussels regularly, you might want to supplement the omega 3 fatty acids.

The digestive tract needs some insoluble fibers in the diet to not get constipation. But it doesn't need them every day and not in huge quantities. So if you have the occasional random vegetables in your diet, that should be covered. It's trivial to know when it's not enough because avoiding constipation is really all the insoluble fibers do.

What's left is carbohydrates and fats. Any will do. And if you are in an industrialized nation, you likely got them covered.
But some sugars are really spiking insulin production, stress the system, and can lead to sugar highs and lows. So try not too eat too many sweets or soft drinks in one session.

The last thing is calories/energy. If you got too few, you need to eat more carbohydrates and fats. If you got too many, you need to eat less carbohydrates and fats. But as is blatantly obvious by now that isn't really actionable advice.
I guess, for undersupply, the solution could be to fatten up the diet and sweating stuff with with lactose if not lactose intolerant. But anyone having this problem in an industrialized nation probably also has more serious problems that cause it.
For oversupply there is no real solution for most people apart maybe Ozempic because constantly fighting one's own appetite is basically impossible for normal people. Just don't start smoking to loose weight. It probably works, but it comes with its own problems.

It depends on the person and the health issues you have or are predisposed to. Talk to your PCP, GI doctor, or registered dietician to find out what's healthy for your body.

If you have no health issues and your older relatives have only died peacefully in their sleep at 100 years old, congrats, don't worry about it, and fuck off with your good genetics. I hate you.

But seriously, what's healthy for one person might be unhealthy for another. And, oftentimes, what's branded as healthy is really just recommendations specifically for people trying to lose weight...in the same way Cady recommended those "weight loss" bars to Regina George in Mean Girls. So maybe that's why it seems no one can agree on what's healthy.

Healthy to me is lots of salads with different greens and vegetables, small amounts of fish or chicken, and fresh green tea.

People do agree.

Almost everyone who studies this stuff professional agrees that the following are bad, and should be limited:

• High sugar, low fiber foods: soft drinks, candy, donuts, cake, ice cream, most other classic desserts.
• Oily/fatty processed foods: chips, certain crackers, shelf stable baked goods like cookies, donuts, wrapped cakes, really greasy pizza.
• Trans fats
• Alcohol

Almost everyone agrees that the following are good, and should be maximized:

• Leafy vegetables
• Colorful vegetables
• Beans, peas, chickpeas, lentils, other cooked legumes/pulses
• Fermented/pickled vegetables, especially through lactic acid fermentation

It's not universal, but it's a pretty broad consensus that the Mediterranean diet is good for you, which includes a lot of:

• Fish, especially fatty fish low on the food chain, like sardines and anchovies
• Other seafood, especially those low on the food chain
• Whole fruit
• Nuts
• Extra virgin olive oil in reasonable quantities

It's also not universal, but the broad consensus is that the following are bad for you when eaten in excess:

• Cured meats like sausage/ham
• Fried foods
• Red meat
• Low fiber white starches (white bread, white pasta, white rice)

For me personally, I eat a lot. I want to eat a lot. I could win amateur eating contests in my youth, and even today, left to my own devices, I have no trouble eating 2000 calories in a single meal, 5000 calories in a single day. So I need to manage my hunger, and I've found that for me, fiber and protein promote satiety, so I eat a lot of legumes: beans, lentils, green beans, peas, peanuts. These are basically my staple food, and I drink a lot of water, and eat a lot of watery foods (fruit, soup, etc.).

I mostly avoid processed sugar (no sugary drinks or candy or desserts). I leave fried foods, which I love, for special occasions. I have seriously reduced my consumption of red meat, almost to zero, mainly out of social responsibility, but also with an eye towards health.

I avoid bringing unhealthy foods into my house. It's a lot easier to avoid eating them when I would have to go out of my way to order it.

I'm also working out all the time. Not just to buy me a calorie budget for eating, but also because knowing I need to go to the gym later helps control my portions and choices earlier in the day. Nothing worse than trying to squat 330+ lbs (150+ kg) with a huge portion of greasy fried chicken sitting in your stomach.

You eat food and then you notice how you feel afterwards, that's the only way. People are very, very different genetically, and while studies show you the average, people can be very unique in what food their bodies does well at digesting.

You eat something and you feel heavy, sluggish, tired afterwards? You either ate too much, or something not good for you, or both.

You eat something and you feel like you didn't really get any nutrition from it and you can just keep eating and you still won't get satisfied? You're probably eating junk not because your body wants it, but because you're trying to avoid some emotions, and so on.

Awareness is king, as always, you cannot adhere to a fixed system as a living organism; you must actually use your senses in each moment.

Just do the basics right. Make healthy choices easier and unhealthy choices harder.

Drink enough water, skip sodas. Eat more green produce, fibre and protein. Buy spices and cook simple dishes that don't require much time.

I like Ethan Chlebowski for food tips.

“Eat food. Not too much. Mostly plants.” Michael Pollan, In Defense of Food: An Eater's Manifesto.

nobody can seem to agree on what a ‘healthy diet’

You're wrong but it's OK. Eat vegetables. " Things that are green " if it helps you. Not too much meat, not too much bread and pasta. That's it, it's easy. 2 or 3 times a day, not more. Stop eating sugar.

soup

These two people

Liam

and

Kylie

They both have degrees in this stuff. They focus on easy realistic healthy eating. You don't have to give up pizza, just eat a little less and add a salad. You don't have to give up brownies, just add beans for more fiber (trust the process, seriously). You don't have to give up instant ramen, just add some veggies. It's really not as hard as it's made out to be and they both do a very good job showing that.

Given than nobody can seem to agree on what a ‘healthy diet’ looks like

as a side quest I recommend working on how to distinguish credible sources of information from not

Try to get 30 grams of fiber a day. Limit processed foods. Limit saturated fats.

I eat a lot of salads with avocado. Oatmeal with dried fruit. Beans and rice.

I had high cholesterol and was overweight. Changing my diet fixed these issues and made me feel better.

You don’t have to have a perfect diet (trying too hard to get one ends up being bad for you), you just have to do enough of the things mentioned here.

I don’t. But when I do, lots of water, a mutivitamin, and one meal per day. I try to follow the Whole30 portioning rules, as well. Palm-sized protein, a fat source, and the rest of the plate is veggies.

A very simple, though hardly practical rule to follow perfectly is: “Avoid things with ingredient lists.”

Michael Pollan as mentioned elsewhere “eat food, mostly plants, not too much.”

“Avoid the centre of the grocery store” assuming a North American layout (which has regional variations) - the point being that the prepared foods are in the middle, the outside edges are butcher, dairy, and produce.

Some asshole once said, “Eat meat and vegetables, nuts and seeds, some fruit, little starch and no sugar. Keep intake to levels that will support exercise but not body fat.” This is also good advice, despite the source.

Im way to lazy to eat healthy. I at most try to choose healthy options when I can. pretty much looking for more fiber and protein and less sugar and fat. also healthier fats which is basically unsaturated. then also more vitamins the better.

The science is actually clear: Mediterranean diet extends life. Mediterranean diet + wine extends it even more.

This means:

• avoid red meat
• eat a lot of legumes (yes, beans!). stews prepared on the base of tomato are really good for you*
• eat vegetables
• eat fish
• add some nuts and fruit
• some white meat is ok
• glass of wine a day

It's scientifically proven that this is good for you.

*look for traditional Spanish recipes for fabada, lentejas, garbanzos etc.

I need to consciously try to eat more vegetables. I should under no circumstances be left unsupervised with candy/chips/cake etc.

I eat about 150-200g of meat per serving and then about twice that by volume on the plate of vegetables. I can only be bothered to eat twice a day.

It's something I can stick with and it's about the minimum I can eat before I start raiding the fridge.

If you made it yourself from ingredients, and it has some veggies and not too much meat

Well, my healthy eating has changed over the years, so these are the various methods I've used.

• See food diet: See food? Eat it. I had several growth spurts growing up and was a 3 sport athlete, so I was always hungry. My mom started claiming that I have hollow legs because I ate so much. There was always at least 1 large veggie side, but often several sides of veggies. Things changed in college.

• One plate diet: modified see food diet. In college, all my growth spurts ended and I was no longer in sports, so my freshman 15 was actually my freshman 50. Things had to change, but I wasn't willing to restrict my food options. So as long as I kept my food limited to a single plate, things were good. Another emphasis on lots of veggies here, with only a single plate I got more veggies. And pizza because it stacks well, but veggies are the important part. As I shifted into the adult world, my diet changed again

• Keto diet: low carb, med protein diet. I wanted to reduce my meat intake and actually eat healthy, so my ex and I did keto for about 2 years. It was actually good, the best recipes were the ones that didn't try to be meat replacements, they just did their own thing. There are dishes that I still make from this period, simply because it's good food.

• One meal per day intermittent fasting: when I was hired by Activision, we had a benefit where the company would provide us with $18 for lunch from local restaurants. That allowed me to only eat 1 meal per day, and fast on weekends. It came to disaster when I was fired, so I changed things again

• Homemade Vegetarian-flexible: my current diet. I've decided that many things, including meat, is too expensive. Meat in particular is not worth killing our planet over, so I've changed things. I make my bread at home. I source as much as possible farmers markets, with plans to start growing hydroponic food crops. I'm removing heavily processed food as well. I've cooked enough foods that I can just kinda wing it with the veggies and get something good. I plan to use paneer as a meat replacement in certain dishes (tacos, chilli, hotdish, etc), but still less frequent than when I was eating meat. I try to avoid meat, but I won't say no to a dish with meat in it

Ive been trying to use my forced return to the office and soaring lunch food prices to my advantage by bringing various vegetables & fruits (celery, carrots, peppers, oranges bananas, etc) to the office to eat throughout the day rather than have a sit down lunch. Extra bonus to that is i can then spend my hour long lunch sitting outside reading a book.

The same stuff I liked in my 20s but the low sodium versions.

Cry more, eat less.

• Tom Segura

lol