We asked a dietitian what anyone who wants to start eating healthier should do - here are his 3 best tips

I've tried all kinds of eating plans. From giving up gluten (yes, I'll admit it) to going vegan for a year, chances are there isn't a wacky diet I haven't at least attempted.

And while I'm well aware of the limitations of one-person studies, I've always been slightly satisfied - in my own smug way - to find that not one of these diets has had long-lasting results. Sometimes, they even seem to do the opposite of what they promised.

With that in mind, I recently chatted with registered dietitian and nutritionist Andy Bellatti to find out how to start eating healthier without falling for a silly diet plan.

Here are his top three pointers:

1. Eat real food.

Writer Michael Pollan said it best: "Eat food. Not too much. Mostly plants."

Be sure to incorporate fresh vegetables, like broccoli, bell peppers, and Brussels sprouts, into any eating plan. These crunchy, colorful foods - which the CDC actually calls "powerhouse foods" - are a great source of key vitamins and nutrients. They're also high in fiber, which helps keep you feeling full and satisfied until your next meal.

That means that things that are not real food are warning signs. "Powders and pills are red flag number one," Bellatti told Business Insider.

The problem with these concoctions, he says, is that they've taken part of something that was once a whole food, like a fruit or a vegetable, then separated and processed it for one ingredient. That's OK for things like cocoa powder, which does have nutrients, but it shouldn't make up the bulk of your eating regimen.

"When something is a powder, you're probably using what, a teaspoon or tablespoon at most? And you have to wonder how much that can really do. Versus a cup of broccoli or a quarter cup of cashews. That's something significant," says Bellatti.

2. Look for ingredients with measurable benefits.

Most health guidelines are based around specific, measurable benefits, from drinking a certain amount of water each day (end goal: stay hydrated) to eating a specified amount of protein (end goal: maintain and build muscles).

Most of these rules are specific to you, however, because they depend on other lifestyle factors like your height, weight, gender, and the amount of exercise you get each day. Other guidelines are more applicable to everyone, like eating enough fiber to keep your digestive system running smoothly and getting enough calcium to protect your bones.

On the other hand, if you see a label that promises to do things like "Harmonize your aura," chances are it won't do much of anything at all.

One problem with putting slogans like these on health products, says Bellatti, is that they're "completely subjective. They can't be tested." In other words, there's no way of knowing whether a product that claims to "bring you in line with your true self" is really doing so.

And, as Bellatti points out, "The person whose word you're taking is the person who's profiting from this."

3. Find a lifestyle mentor.

You don't necessarily need to subscribe to a specific meal plan or banish certain foods from your diet to start feeling and looking better. For starters, Bellatti suggests simply reaching out to people close to you who are living the lifestyle you want.

"What I would do if I wanted to get healthier is I would look at my friends and family members who are living the life I want to have and I'd say, 'what are they doing?'" says Bellatti.

"The people in your life who are the healthiest are probably doing practical things: not drinking much soda, eating very little fast food, getting enough fiber in their diet."

That said, you can probably ignore diet plans that simply don't align with common sense. Does "cleaning out your system" with a lemon juice and maple syrup "detox" sound too easy to be true? It probably is. Similarly, any diet plan that claims it can "give you glowing skin in 24 hours" or "make you feel like a new person" is probably being a bit overzealous.