Healthy or Hoax is a new podcast series from RNZ that looks at the new-fangled fads and tempting new trends and asks if they're really up to much. In short: Do. They. Work? Presented by Carol Hirschfeld, with help from food writer Niki Bezzant and a host of experts, the series will report on the latest things in food, fitness and leisure and ask if they're all hype or if they're actually good for you.

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Kate Pereyra Garcia documents her three weeks eating coconut oil in part one of Healthy or Hoax, a new podcast series looking at the facts behind current health trends. Does it live up to the hype?

By Kate Pereyra Garcia

The proponents of coconut oil make a lot of promises.

So when someone was needed as a human guinea pig for RNZ's Healthy or Hoax podcast, I volunteered.

Lose weight, lower cholesterol and prevent wrinkles? Simply by eating oil?

If it works: amazing.

The claims around the medical properties of coconut oil have burgeoned in recent times, with bold claims online that it's "one of the healthiest foods on the planet" with "life-saving" properties. Beyond the more superficial claims about weight loss, building muscles and stopping wrinkles, its supporters suggest it may prevent Alzheimer's, heart disease and some cancers.

If even half of the claims were true, it would be a miracle cure. So, although some scientists are pretty sceptical, it's not hard to see why more people are buying it.

New Zealand supermarkets had a 15 percent year-on-year increase in sales.

Countdown spokesperson James Walker said it was part of a trend across the entire supermarket for specialty health foods. For its part, Foodstuffs confirmed New Zealand supermarkets sold more than $7 million worth of coconut oil in the year to March.

So I was in good company when I popped into my local New World to purchase a tub for the experiment.

It was completely non-scientific, of course, but the idea was to consume at least a tablespoon a day for three weeks. I did a blood test to check cholesterol levels before and after.

Consultant Laurence Eyres conducted a major review of studies of coconut oil for the Heart Foundation, which was published last year in the Nutrition Reviews journal. He didn't find one peer-reviewed study showing any benefit of using coconut oil.

"The claims for curing Alzheimer's or cancer or what have you were based on marketing hype and had no foundation."

So on the serious science, there's no evidence to endorse the claims, though one Otago University study showed coconut oil wasn't quite as bad as butter when it came to raising cholesterol levels.

Auckland University of Technology Professor of Public Health Grant Schofield said coconut oil was not necessarily bad for you, but there was no evidence it would live up to the more extreme claims.

So how did my experiment go?

The first week was fine, I mainly used the coconut oil to fry vegetables each night. By the middle of the second week I was sick of stir-fried dinner and over everything tasting like coconut…

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Carol Hirschfeld hits the gym for some High Intensity Interval Training and finds it can take you up a notch... If you fit the bill. So is HIIT right for you?

By Kate Pereyra Garcia

Watch a video segment from the episode here

Anyone who belongs to a gym has probably done it. Even those who don't have probably heard of it.

High Intensity Interval Training (HIIT) has had a lot of media coverage in recent years for being a quick fitness fix for anyone short of time; which is pretty much everyone, right?

Even RNZ has discussed its benefits.

HIIT is essentially short, intense bouts of exercise interspersed with periods of rest. It's the antithesis of long steady cardio training. Some of the more well-known studies involve participants sprinting on stationary bikes for one minute intervals at a maximum pace versus slow continuous pedaling.

As the Healthy or Hoax podcast team, led by host Carol Hirschfeld, found out HIIT definitely has some benefits. The most obvious is that you can finish a workout in 20 minutes instead of an hour... or more.

Performance physiologist and AUT adjunct professor Paul Laursen said studies showed participants achieved as much, if not more, in the shorter time.

"You wind up being able to accumulate a greater amount of hard work than if you were just going to perform that same amount of work continuous.

"So by breaking it up you get a longer period total of high intensity work."

But, Dr Laursen warned HIIT is not necessarily as good as it sounds.

"Sometimes it's just interpreted as 'all I need to do is go out and kill myself', and of course we've all got pretty busy lives, we're under a lot of stress, sometimes we're not always on the healthiest diet, so there's loads of different stressors."

In that case, adding further stress in the form of high intensity exercise is asking for trouble, he said.

"You can really speed your way to over training... ultimately you can make yourself sick, or feel run down, and you can injure yourself as well."

One to three HIIT workouts a week should be the maximum, Dr Laursen said.

Les Mills head of research Bryce Hastings said the gym's HIIT classes were for people who already exercise consistently.

"You might be up to five days a week.. and when you've got that going and you're pretty comfortable there and people are wanting that next level of improvement - that's where we see HIIT as being really really useful."

The most important thing was to be moving consistently, he added.

Fitness instructor Chris Richardson is a HIIT convert…

Go to this episode on rnz.co.nz for more details