Kayla Itsines debunks two 'healthy eating' myths that refuse to die.

We’re all familiar with the saying ‘you can’t believe everything you read’, but that hasn’t stopped the spread of spurious health information that isn’t corroborated by any kind of scientific evidence.

Social media and the wider internet are full of these claims, and in some cases they can sound just legit enough to be true — and thus, myths are born.

In a new blog post, personal trainer Kayla Itsines takes aim at four of the most common non-truths about nutrition.

“It can be super confusing and overwhelming to sift through all the information out there. The internet has allowed many people to put in their two cents about every topic under the sun,” the Bikini Body Guide founder writes.

Can’t wait to see all my #bbg girls OMG ????????☺️ I’m so nervous !!!! Argh! P.s if ANYONE sees me out with my team anywhere in London, NYC or LA, come say hello to us ???? www.kaylaitsines.com/app

A photo posted by Kayla Itsines (@kayla_itsines) on Jun 12, 2016 at 4:46am PDT

Here are two of the myths Itsines debunks:

1. ‘100 per cent fruit juice is just as good for you as whole fruit’

Fruit juice always seems like such a healthy option — and it comes with a side of convenience. Who wants to eat an apple, an orange and a big hunk of pineapple when you can just drink them through a straw, right?

Sadly, by drinking those “100 per cent” fruit juices, even the ones that are made right in front of your eyes at your local juice bar, or by you in the comfort of your own home, you’re missing out on some of the good stuff found in whole fruit.

“One of the most nutritious parts of a fruit is the pulp and skin, because they contain fibre… When we buy fruit juice from the shops, the pulp and skin is often removed during processing, so ultimately you are left with a bottle of fruit sugar,” Itsines explains.

“While there is nothing wrong with fruit sugars when eaten in the right amounts, drinking bottled juice can make it super easy to consume a lot of it in a short period of time.”

Image: iStock

Even though this sugar is natural, there can be implications of consuming too much of it.

“[Natural sugars] have a tendency to give the individual extreme blood glucose fluctuations — this happens when the blood glucose levels rise and fall rapidly and has the ability to cause havoc with brain function and overall energy levels,” nutritionist Samantha Turner told Mamamia.

Juices can also lead you to consume way more fruit than you need to in one go.

"When you eat an apple for a mid-morning snack, you generally just eat one, right? However, when you make an apple juice, you might add two, three or even four apples to create a decent amount of juice," Itsines adds.

Watch: The amount of sugar in your favourite drinks might surprise you. (Post continues after video.)

2. 'Fresh vegetables are better than frozen ones'

Don't turn up your nose at that bag of frozen spinach just yet — the freezer section-variety of your favourite veggies can be just as nutrient-rich as those you buy fresh, if not more.

"A lot of the time, fresh produce can remain ‘in transit’ for several days or even weeks before they reach supermarket shelves. This means that the amount of nutrients the fruit or veggies contain may gradually decrease during this time," Itsines writes.

If it's any further incentive, dietitian Dr Joanna McMillan told Mamamia earlier this year that food freezing processes (along with canning processes) have improved significantly over time.

"[Veggies] are snap-frozen on the day they're picked, so the nutrients are preserved — particularly levels of vitamin C, which are destroyed quite readily through exposure to light and air," she said. (Post continues after gallery.)

Frozen veg is the real deal, in other words — and as Itsines points out, it can be a more affordable option. Time to clear some space in that freezer of yours.

However, there's no denying fresh is a more enjoyable option in some circumstances.

"I don’t know about you girls, but I’m not a fan of soggy spinach in my salads," Itsines says.

True.

What are some health myths you're sick of hearing?

Featured image: Instagram.