Kitchen Tips

The truth about popular diet trends

At the start of a new year, we often think about adopting a new diet. But just how safe are the raft of eating regimens gaining popularity? We get a nutritionist's opinion on four common trends.

1 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 is that following a gluten-free diet is better for you, even if you don’t have coeliac disease. International surveys show one in three people think going gluten-free is healthier, and a similar number believe it will help them lose weight. Some say they feel better when they avoid gluten, and as a result self-diagnose a gluten intolerance.
The science says that unless you have coeliac disease, sticking to a gluten-free diet doesn’t provide any health benefits, and doesn’t improve feelings of wellbeing, digestion or inflammatory responses. Not only can gluten play a role in heart, gut and immune system health, skipping foods which contain wholegrains can deprive your body of essential nutrients, including the B vitamins, dietary fibre, iodine and vitamin E.
So why has going gluten-free become so popular? Food magazine’s nutritionist Bess Kilpatrick Mason says that our bodies are made to digest some gluten; however she believes the popularity of abstaining has been a response to food manufacturers packing gluten into a huge range of products — “so we eat more gluten than our bodies can regularly digest.”
She suggests that rather than cutting out gluten completely, we should be ensuring we eat better forms of it, such as wholemeal bread.
“The problem with gluten-free products is they often have less fibre and are more processed,” says Bess. “It’s interesting to look at the back of the packs and see what has been added in place of gluten.”
A recent study published in The Journal of Pediatrics concluded that pre-emptively starting a gluten-free diet without medical diagnosis can endager health.
Dr Norelle Reilly, who worked on the study, notes, “Gluten-free packaged foods frequently contain a greater density of fat and sugar than their gluten-containing counterparts. Obesity and new-onset insulin resistance have been identified after initiation of a gluten-free diet.”
Those who do lose weight on a gluten-free diet are often those who cut out processed food and desserts completely in a bid to avoid gluten.
Think twice because there’s no advantage in sticking to a gluten-free diet unless you’ve been diagnosed with coeliac disease or gluten intolerance. Bess suggests keeping a food diary for a week to see how much gluten you are having. It may be you simply need to increase the fibre in your diet, which will help your body process the gluten. “Eating more lentils, beans or fiberous fruit such as pears or prunes could make a difference,” she says.

2 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 is that natural sugar in dairy food, called lactose, is to blame for bloating, cramps and wind. While no data is available for New Zealand, one in six Australians are dairy-free – and 74 per cent cite digestive problems as their reason for quitting. Others believe it can cause weight gain and heart disease.
Eating the recommended amount of dairy doesn’t increase heart-disease risk, and it may help weight loss. Plus, health professionals do have some concerns about cutting dairy completely from our diets. Dairy foods are many people’s major source of calcium, so removing them can lead to increased risk of osteoporosis. Dairy also contains other vital nutrients including protein, potassium, vitamin B12 and zinc.
The science says lactose intolerance, which can cause wind and bloating, is relatively rare. Some research shows that eliminating dairy can actually lead to a person developing a lactose intolerance, because it stops production of the enzymes which process it. Furthermore, even people diagnosed with a lactose intolerance don’t need to quit dairy completely — most can tolerate 250ml of milk each day or eat cheese that is low in lactose.
Bess Kilpatrick Mason is open to people going dairy-free — but believes it is important to replace these nutrients. “There are vegans who are totally healthy and have found other ways to get calcium, phosphorus and other minerals without having dairy,” she says. “But if you have growing kids who aren’t having dairy you need to be very intentional about how they get their calcium and vitamin D.”
Think twice as 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 1 cup milk, a pottle of yoghurt or two slices of cheese.

3 A paleo diet

It involves cutting out dairy, 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 is that the human body is better suited to eating like our caveman ancestors did, before farming influenced our diets. According to proponents, 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 has transpired 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 with weight loss. While one overseas study found that people on the eating regimen lost 2kg more in four weeks than those sticking to national dietary guidelines, other research suggests following a paleo diet for two months can cause weight gain and health complications, including increased insulin levels.
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. “Paleo is pretty much the Atkins diet relived; it’s just got a few more greens in it, and it’s all organic and local,” says Bess Kilpatrick Mason.
“I’ve had clients who have lost weight on paleo, but they can’t sustain it because they can’t afford to be buying these foods all the time and their kids aren’t enjoying it because they can’t even have a slice of bread. Many have no energy because they’re not having carbs or fibre.”
Think twice because a paleo diet has some pros and cons. It’s rich in fruit and vegetables, as well as healthy fats, fish and meat. Cutting out refined carbohydrates and highly processed foods is also a plus. Dietician Tania Ferraretto concedes paleo does include some healthy foods; “but it also excludes important nutrient-rich foods like wholegrains and dairy,” she says.
Even the scientists who proved the weight-loss results associated with going paleo are wary. “The paleo diet markedly reduces calcium intake because it excludes all dairy products,” says Angela Genoni of Edith Cowan University. “This could have a negative impact on bone strength, particularly in older people.”

4 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 is 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 New Zealanders need to cut down on their sugar intake. On average Kiwis consume 54kg of sugar a year, or 37 teaspoons per day. The World Health Organisation recommends just six teaspoons per day for adults and three for children.
Regularly consuming high-sugar foods and sweet drinks not only leads to weight gain, it also increases the risk of stroke and shortens the life span. This is because 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 much more likely.
However, many health experts are concerned about the hype around going sugar-free. “I think ‘sugar-free’ needs a bit more education around it,” says Bess Kilpatrick Mason. “Fruits are nature’s way of giving us sweet food, plus sugars are our most efficient form of energy.”
Tania Ferraretto is equally cautious of following a sugar-free diet. She says, “Some foods that a strict sugar-free diet eliminates are rich in fibre, protein, vitamins, minerals and phytonutrients. For example, many healthy foods – such as fruit and dairy food – contain sugar.”
Think twice because while we do eat way too much sugar, “we should keep natural sugars, such as yoghurt and fruit, in our diets,” says Bess, who warns against removing treats completely. “Pick that one thing that you really love and make it not an everyday, but a treat — because if you take it out you become a bit obsessed.”
The key is watching out for sugar added to packaged items and those we consume in liquid form – whether in juices and alcohol, or in tea and coffee.
“You might find that even a beautiful smoothie has a whole lot of sugar you weren’t expecting,” says Bess, adding that for successful sugar reduction, we need to do it, “slowly, wisely and by making sustainable choices.”

Little tweaks for big results

Food magazine nutritionist Bess Kilpatrick Mason believes we can learn something from these popular eating regimens. “Most diets that gain traction have 70 per cent of good values in them,” she says. However, she warns they are often unsustainable, and the health risks can go deeper than the purely physical. “One of the negatives I see is orthorexia – an unhealthy obsession with eating healthy food.”
If you are looking to lose weight and keep it off, Bess suggests making small lifestyle tweaks rather than following a food fad. Try:
● Shifting from full to low fat milk.
● Cutting out all sugary drinks Monday to Friday.
● Limiting the number of takeaways and ready meals you have each week.
● Adding one piece of fruit to your diet each day.
● Walking for 30 minutes five days a week.
Feature photograph by : Andrew Finlayson/
This first appeared in Food magazine.
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