Quitting sugar, going paleo and eating gluten free are popular food trends, but are they actually good for you? Karen Fittall goes in search of the hard facts.
On the face of it eating less sugar, saying no to refined carbohydrates and making sure your diet contains plenty of fresh produce sounds like a good idea. And to some extent, going gluten free, eliminating sugar and following a paleo diet are three ‘eating trends’ that can help you achieve all of those things. But are they really effective for improving your health and controlling your weight? Or could they have the opposite effect? Here’s what you need to know.
A GLUTEN-FREE DIET
It involves: avoiding foods that contain gluten, a protein in wheat, rye, barley and oats. It takes a lot of healthy foods like wholegrain bread, pasta and cereals off the menu.
The idea behind it: that a gluten-free diet is healthier, even for people who don’t have coeliac disease. One in three people believes that’s true, and a similar number think going gluten free will help them lose weight. Some people also say they feel better when they avoid gluten, and self-diagnose themselves with a gluten intolerance, as a result.
The science says: that sticking to a gluten-free diet doesn’t provide any health benefits for the general population, and doesn’t improve feelings of wellbeing, digestion or inflammatory responses. In fact, not only can gluten play a role in heart, gut and immune system health, unnecessarily sticking to a gluten-free diet increases the risk of nutrient deficiency, partly because you’re skipping foods that contain wholegrains. “The potential ‘at-risk’ nutrients include the B vitamins, dietary fibre, iodine and vitamin E,” says Dietitians Association of Australia spokesperson Tania Ferraretto. “Plus, going gluten free has absolutely no benefit for weight loss.” Research shows that gluten-free foods can actually lead to weight gain, because they often contain extra fat and sugar compared to their gluten-containing equivalents.
So why do people who haven’t been diagnosed with an intolerance say they feel better when they quit gluten? One explanation is that to avoid gluten they cut out desserts and processed foods, which leads to weight loss. Another is that they may be intolerant to the fructans in wheat.
Fructans are a type of FODMAP, a group of dietary sugars that can cause uncomfortable digestive symptoms for some people. While that can mean following a low-FODMAP diet for a period of time is a good idea, it doesn’t require avoiding other glutencontaining foods like oats or quitting wheat full-time.
Think twice: There’s no advantage in sticking to a gluten-free diet unless you’ve been diagnosed with coeliac disease or gluten intolerance. “If you suspect you might have a gluten intolerance, talk to your doctor about getting a proper medical diagnosis,” says Ferraretto.
A SUGAR-FREE DIET
It involves: eliminating sugary foods, both processed varieties that contain added sugar, like cakes, drinks and breakfast cereals and, in extreme forms of the diet, foods that contain natural sugars too, such as fruit.
The idea behind it: that sugar causes everything from weight gain and dental problems, to heart disease and faster ageing. Some research has even suggested that sugar is addictive, because it affects the same neural pathways that some drugs tap into.
The science says: That Australians need to cut down on their sugar intake. More than 50 per cent of us eat too much added sugar – up to 27 teaspoons per day, on average. And regularly consuming high-sugar foods and drinks, like fizzy drinks, does increase the risk of stroke and shorten your life span. The reason? The high sugar load accelerates the ageing process, as well as causing insulin resistance and inflammation, which makes hardening of the arteries and blood clots more likely.
But many health experts believe completely ditching sugar from your diet can be harmful because you risk missing out on other importants nutrients in the foods you cut out. “Some foods that a strict sugar-free diet eliminates are rich in fibre, protein, vitamins, minerals and phytonutrients,” says Ferraretto. “For example, many healthy foods – like fruit and dairy food – contain some sugar.”
Think twice: “While eating foods high in added sugar can contribute to tooth decay and weight gain, there’s no need to completely eliminate sugar from your diet,” says Ferraretto.
So keep eating fruit and dairy foods, but do cut back on ‘free sugars’, which are the ones that are added to foods and drinks by the manufacturer, a chef or yourself, and also watch out for products with naturally occurring sugars such as honey and fruit juice. Try to stick to no more than 50g, but ideally 25g, or six teaspoons, of that type of sugar a day. Preferably, choose foods that contain less than 5g of sugar per 100g, but up to 15g is okay.
Likewise drinks should ideally contain less than 2.5g of sugar per 100ml, but up to 7.5g is okay.
A PALEO DIET
It involves: cutting out dairy food, grains and legumes and sticking to a diet of meat, fish, eggs, vegetables, fruits, nuts and seeds. Highly processed foods and salt are also out, and devout paleo eaters don’t eat potatoes either.
The idea behind it: the human body is better suited to eating like our caveman ancestors did, before farming influenced our diets. According to the paleo diet, the introduction of grains, dairy and legumes outpaced the body’s ability to adapt and properly digest them, so it’s those foods that increase the risk of obesity and ‘lifestyle’ diseases like diabetes and heart disease.
The science says: that the human brain wouldn’t have evolved like it has if cavemen really did eat today’s paleo diet, which avoids starch-rich vegetables and grains. It turns out that starchy carbohydrates, along with meat, were responsible for the increase in the size of the human brain 800,000 years ago. There’s also conflicting evidence about whether a paleo diet helps weight loss. While one study found that people who ‘went paleo’ lost
2kg more in four weeks than those sticking to the Australian Dietary Guidelines, other research suggests following a paleo diet for two months caused weight gain and health complications, including increased insulin levels. And even when paleo diets were linked to improvements in blood pressure and cholesterol levels, it was likely a result of weight loss, not the diet itself. On the other hand, diets rich in legumes and wholegrains reduce the risk of both heart disease and diabetes, independent of weight loss.
Think twice: A paleo diet has a fair few positives. It’s rich in fruit and vegetables, as well as healthy fats, fish and meat – a good source of protein, iron, zinc and vitamin B12. Cutting out refined carbohydrates and highly processed foods is also a plus. “A paleo diet does include some healthy foods, but it also excludes important nutrient-rich foods like wholegrains and dairy,” says Ferraretto. Even the scientists who proved the greater weight-loss results associated with going paleo are wary: “Despite the greater weight loss, we should be cautious about advocating a diet that cuts out entire food groups,” says Angela Genoni from Edith Cowan University.
“Significantly, the paleo diet markedly reduces calcium intake because it excludes all dairy products, which could have a negative impact on bone strength, particularly in older people.”
A DAIRY-FREE DIET
It involves: steering clear of cow’s milk, cheese and yoghurt, as well as products made using them.
The idea behind it: the natural sugar in dairy food, called lactose, is to blame for bloating, cramps and wind. Of the one in six Australians who has chosen to go ‘dairy free’, 74 per cent cite digestive problems as their reason for quitting. Others avoid it because they think it contributes to weight gain and heart disease.
The science says: not only is lactose intolerance, which can cause wind and bloating, relatively rare, but even people diagnosed with it don’t need to quit dairy completely – they can tolerate 250ml of milk each day and most cheeses are very low in lactose. Eating the recommended amount of dairy doesn’t increase heart-disease risk, and it may actually help weight loss. Plus, ditching dairy can be a health risk. Dairy foods are the major source of calcium in most people’s diets, so removing them can lead to increased risk of osteoporosis. And they also contain other vital nutrients including protein, potassium, vitamin B12 and zinc.
Think twice: There’s no reason to eliminate dairy, even if you have been diagnosed with lactose intolerance. Women should eat 2.5 serves of dairy each day, increasing to four if you’re over 51. A serve is 250ml milk, 200g yoghurt or 40g hard cheese.