Should we still be eating five-plus-a-day or can we get away with just three portions of raw veg a day? Photo / Getty Images
By Madeleine Howell
Are fats really that bad for you? Will cutting back on them help you to lose weight? And should you be eating the recommended five-a-day?
Not necessarily, according to new studies that are calling into question the nutrition gospel that would-be healthy eaters have lived by in recent years.
In one study, by the McMaster University in Ontario, lower fat diets were found to actually shorten your lifespan. The foods substituted for meat and dairy appeared to do more harm than good.
The study showed that refined carbohydrates including white bread and rice are a more significant threat to good health than saturated fats from animal products. As a result, the Canadian researchers have called for global dietary guidelines to be revised.
Meanwhile, research from the European Society of Cardiology Congress in Barcelona has suggested that just three or four servings of raw vegetables can be as beneficial as five servings or more of fruit or veg a day. The same study found that those with a low intake of saturated fat had a 13pc higher chance of early death compared to those who eat plenty.
These findings seem to contradict advice on saturated fats and a study led by Imperial College London earlier this year that suggested we should be aiming for up to 10-a-day for the best chance of avoiding chronic diseases or an early death.
In the wake of the latest findings, here's some other surprising healthy eating "laws" that might be more fiction than fact:
We were pleased to find out that this one isn't necessarily true. The handful of scientific studies into the subject have found little by way of conclusive evidence that chocolate does indeed lead to pesky spots.
According to Rhiannon Lambert, a Harley Street nutritionist, the nutritional value - or lack of - in your chocolate fix depends on the composition of the chocolate and sugar content. Broadly speaking, dark chocolate contains less sugar, so it's less likely to lead to fatty weight gain.
However, if you are intolerant to dairy, this may cause spots to flare up.
Verdict: Mainly false
Lambert warns that substituting the fat content in your favourite food (low-fat yoghurt, for example) with sugar to replace the tastes of the lost fats can often be worse for you than the natural product itself.
"It's of zero value to us nutritionally," she explains. "As a result, added sugar is unquestionably the single worst ingredient in the modern diet." Meanwhile, the NHS warns that eating too much sugar can make you gain weight and can also cause tooth decay (sugar found naturally in milk, fruit and vegetables doesn't count).
Verdict: False
While Lambert herself enjoys drinking almond milk, she admits that it is mainly made up of water and often lacks the nutritional value to be found in dairy milk.
If you're intolerant to dairy, she advises that you make sure to pick a fortified almond milk to make sure you don't miss out on essential calcium.
Verdict: True and false. It won't harm you, but it won't do you loads of good either
Surprisingly, this one has substance. Carrots contain Vitamin A and retinol, which is linked to rhodopsin, the pigment in our eyes which operates in low light conditions. It can also be found in sweet potato and other orange-coloured foods.
Verdict: True
"There's no scientific link between coffee and cellulite," Lambert explains. "Cellulite is more prominent in women and is to do with the structure of fat cells and with circulation. While extra fluids can cause more to appear, the best way to reduce their appearance is to stay hydrated and to improve your circulation."
Verdict: False
Lambert says 10 portions of fruit and vegetables should be the goal - although the 5-a-day set out by the NHS based on recommendations from the World Health Organisations is a good place to start. "It's not just that they provide vitamins, but the variety is good for your gut and for the absorption of nutrition too."
Whether you try to incorporate a minimum of three raw vegetable servings in your diet, eat your 5-a-day religiously or aim for 10 portions and beyond, it's clear that either way, there's little disadvantage to eating more fruit and veg.
Verdict: The jury remains undecided
Prefer an egg white omelette over classic scrambled egg or poached eggs? Our nutritionist stresses that the nutrition in the yolk is important too, and won't contribute to cholesterol as it is often believed.
Here in the UK we are often deficient in Vitamin D, and egg yolks are a great source of it. So get cracking.
Verdict: False
Foods containing gluten should only be a problem for the 1pc of the population who are coeliacs (ie. lacking in the enzyme required to break it down) or who have a genuine sensitivity. Many gluten-free foods on the market could in fact be considered unhealthy, since they would be tasteless without the higher levels of sugar, salt, and other additives used to make them more palatable.
"You should only be avoiding gluten if you have been diagnosed with coeliac disease or have a gluten intolerance," says Lambert. "Gluten is predominately found in carbohydrate-based foods like rye, barley and wheat, although it is also found in the unhealthiest items such as pastries, cakes and biscuits.
Harley Street nutritionist Rhiannon Lambert sorts the fact from the fiction.
Is fat really that bad for us, and why do we need to eat fat?
Not at all. Fat is needed in the diet for energy and to support cellular growth. Healthy fat affects vitamin absorption affects vitamin absorption for vitamins A, D, E and K and are actually linked to improving heart health.
Does a low-fat diet necessarily translate into weight loss?
Weight loss is to do with an energy balance, so it's actually restricting your energy intake that equates to losing weight. Low-fat can actually be detrimental as often products have added sugar to re-create the taste missing from the fat, and then body is also missing out on essential nutrition.
Are refined carbohydrates unhealthy, and why?
Carbohydrates in themselves aren't bad, and we need glucose for energy. There is a difference between complex and refined carbohydrates, but a portion of white rice at your favourite Thai restaurant isn't the end of the world.
How can we strike a healthy balance?
Every food group has a purpose. A balanced plate with portions of fat, vegetables, protein and carbohydrate is the key to a healthy balance. Everyone is unique, but the ideal is the 80-20 ratio - if you eat well 80% of the time, 20% of the time you can get away with treating yourself.