For years we feared eggs only to find they're good for us after all -- or are they? Is fat-free really the way forward or does that guilt-free label conceal hidden dangers? And just where do we stand on carbs?
In today's diet-obsessed world there's a feast of information available about what foods to eat and which to avoid.
But unfortunately the options are often contradictory and it's not always clear whose advice we should swallow.
In a bid to clear up some of these dilemmas once and for all, Chrissie Russell tracked down five experts to ask them what are the five foods they personally would never let past their lips?
PATRICK HOLFORD - Founder of the Institute for Optimum Nutrition
The ingredients are disgustingly clever -- high fructose corn syrup is sweet but doesn't trigger the 'satisfaction' reaction that you get with glucose, while caffeine gives you a buzz and makes you pee and sodium makes you thirsty making you drink more!
It's incredibly high in fast-releasing sugar. I prefer to eat my fruit not drink it since nature always provides fibre.
They are really high in fast-releasing sugars and if you don't want a muffin top later in life you have to control sugar. I'd only have a banana if I was about to climb a mountain or go for a bike ride. Berries, cherries and plums have a very slow-releasing sugar which is much better.
Non free range eggs
Have you seen battery hens? They can hardly stand. While I would advocate organic meat or fish, I've noticed that very few people in restaurants ever ask about where the eggs have come from.
The better you feed chickens the healthier their eggs are and they don't raise your cholesterol. Eggs are a good food if they come from a good source.
There are 50 permitted additives in wine, including milk (which I'm allergic to)! Much of the taste in cheap wines comes from flavoured yeasts.
Many people react to the chemicals so organic wine really does make you feel much better the next day. Champagne is yeast free and organic brands are my favourite.
On the subject of milk, I don't actually eat dairy either. I think generally we all eat too much of it. Name me a mammal that consumes milk as an adult?
Dairy products aren't part of our natural design -- they're designed to make calves turn into big fat cows. I'd advocate less or none if you're allergic.
Patrick Holford will be lecturing at the Rude Health Show in Dublin next month
ELSA JONES - Nutritional Therapist and presenter of TV3's ‘How Healthy Are You?’
I see so many people fall into the trap of buying diet yogurts, thinking they are choosing the healthy option when in actual fact most diet yogurts on the market contain at least four teaspoons of sugar per small pot.
Grams don't tend to mean anything to people but a good way to gauge is to remember that one teaspoon of sugar is the equivalent of 4g.
Studies have shown that regularly eating processed meat like sausages and rashers significantly increases the risk of developing bowel cancer.
The World Cancer Research Fund recommends we avoid processed meats altogether because they're manufactured with a carcinogenic known as sodium nitrate, which turns packaged meats bright red so they look fresh.
The most popular brands of packaged oxtail soup still contain MSG (Monosodium Glutamate) which is an addictive flavour enhancer that causes adverse symptoms in many people.
A double evil in that they're high in two stimulants: caffeine and sugar. The combination wreaks havoc on blood sugar levels and revs up stress hormones which can lead to energy dips, mood swings, increased heart rate, anxiety, insomnia and weight gain.
The ultra-processed variety are often high in hydrogenated fats, salt, colourings and preservatives which can act as anti-nutrients -- foods that have no nutritional value but still require nutrients in order to be processed in the body, in effect robbing us of nutrients.
Regularly eating ready meals can also be addictive because they have the ability to stimulate receptors in the brain to make you feel good.
ORLA WALSH - Dietician with the Dublin Nutrition Centre
Reduced-Fat Peanut Butter
The oil it contains has many nutrients, so there are few advantages to taking the healthy fats away.
In fact, often what happens is that they bump up the sugar content of the food so you're left with less nutrients and a similar calorie content.
Products that boast they're 'multigrain'
Multigrain doesn't always mean wholegrain.
Wholegrain food provides you with the three layers of the grain, therefore giving you the nutrients within each layer. Multigrain doesn't guarantee the same thing.
They often have as many calories as normal muffins -- which is the same as six slices of bread!
Many people imagine granola to be healthy but the sheer amount of sugar and oil used in toasting them can make some brands very high in calories so check the labels.
Refined carbs are generally white in colour, low in fibre and a far cry from how they looked when they grew out of the ground.
They offer very little in nutrition and make it hard to maintain a healthy weight because they don't leave you feeling full.
DR JOEL FUHRMAN - Author of NYT bestseller ‘Eat to Live’
Barbecued meat, processed meat and red meat
Any type of meat, not just red meat, will produce dietary carcinogens when cooked at a high temperature.
But red and processed meats in particular have been consistently linked to cancer in studies, with the American Institute for Cancer Research now deeming them to be a convincing cause of colon cancer.
Scientific studies have also made a link between higher red meat consumption and earlier death.
It's not just the empty calories provided by cooking oils. Studies also show that high heat cooking, like frying, produces acrylamides with starchy foods such as chips or breaded food, which are toxic and potentially cancer-promoting substances.
Cheese, butter, whole milk and ice cream are dangerous, calorie-dense foods loaded with saturated fat.
Contrary to popular belief, artificial sweeteners are not the answer -- they are not even helpful for weight loss and their possible dangers are still unknown.
Sweetened foods enhance appetite and weight gain, even if the calories from the sweetener are insignificant.
Studies have shown that people who use no-calorie sweeteners just want to eat more sweets to satisfy the cravings brought on by the intensely sweet flavours.
White flour products and white rice
Refined carbohydrates like white bread, pasta and rice are not just adding a few extra calories to your diet. They actually induce harmful nutritional deficits and cause cell inflammation. They're devoid of fibre and stripped of vital nutrients and act in the body like sugar -- promoting diabetes.
ESTHER BLUM - US-based dietician, author of ‘Eat, Drink, and Be Gorgeous
Red Dye 40
It's found in junk food and can cause allergy-like reactions. It's also a known carcinogen linked to reproductive problems in rats.
Twinkies (a cream sponge cake popular in the States)
They are completely devoid of nutrition and have a 25-day shelf life which makes me wonder if they're even food. They were even implicated in a 1978 murder case. The 'twinkie defence' was used by Dan White after the murder of Harvey Milk, claiming an unhealthy diet of twinkies had contributed to his depression.
Some companies fed scrap meat treated with ammonia to their patrons so they certainly won't be getting my business. Although some chains have caved in to public pressure and are no longer treating their meat with ammonia, there's just too much wrong in their history to ever be right for me.
Some Peanut Butters
Those with hydrogenated oils present are like metabolic sludge in your cell membranes. Even if you were to stop eating them tomorrow, it will take your body up to two years to displace these toxic fats with good ones.
Veggie burgers and edamame
Soy suppresses thyroid function and can give guys a shrinky dinky. If you ever want to reproduce again or have a functioning thyroid, steer clear.