Will that diet REALLY change your life?

We’re always seeing new trends in nutrition. Nutritionist Rose Carr runs a critical eye over the credibility of the latest diets.

From gluten-free to paleo, lately it seems there’s always another trend popping up promising to be the holy grail of good health and weight loss. Look around and there are countless Hollywood stars praising a new diet for their good looks, while book store shelves groan with the weight of best-selling diets claiming to give you lasting vitality. These plans promise to transform your well-being and are understandably alluring. So, we’ve looked at the science, and show you if some of these diets really can work for you.

The Paleo Diet

Eat like a caveman

There are lots of interpretations of this diet, but the basic premise is to eat in the same way our Paleolithic hunter-gatherer ancestors did about 10,000 years ago.

The diet includes eating a large amount of meat (ideally free-range), fish and seafood as well as fruits, vegetables, seeds and nuts.

Banned are dairy products, grains, legumes, refined sugars and processed foods (eg. sweets, muesli bars, chocolate and crackers), which weren’t on our ancestors’ menu.

A typical day 

• Breakfast: A vegie omelette
• Lunch: A large piece of free-range chicken and raw salad
• Dinner: Grass-fed steak and a raw salad
• Snacks: Nuts, fruit or grilled fish or chicken

Does it work?

This diet is high in protein, fibre, omega-3 fats and other unsaturated fats while being low in the saturated ‘bad’ fat and sodium found in many typical western diets.

By eating only unprocessed foods, you’re cutting out a lot of fat, salt, sugar and the excess kilojoules they can add to your day, which is the main reason for the weight loss.

Studies on 229 remaining hunter-gatherer societies done some time ago found they were largely free of symptoms of heart disease, so following a Paleo diet may reduce your risk.

Most of us would lose weight on this diet (no cheese, no baking, no chocolate, no wine...) and, as it is high in protein and fibre from fruit and veg, it’s filling, too.

Scientific evidence does not support avoiding whole grains, legumes and low-fat dairy just because they weren’t eaten tens of thousands of years ago. These important food groups provide us with essential nutrients.

A high intake of meat may increase your risk of an attack of gout.

Eating more meat over grains and legumes is expensive.

Our expert advice

This is not a diet we would recommend. Cutting out entire food groups (dairy and grains) isn’t advisable as a long term eating plan. However, we can take a lead from our ancestors by eating more unprocessed foods (and so eating less salt, saturated fat and alcohol) and increasing our physical activity.

The low-FODMAP diet

The tummy-friendly diet

FODMAPs is the acronym of a group of carbohydrates which cause common symptoms of Irritable Bowel Syndrome (IBS), such as bloating or diarrhoea, in people who are sensitive.

FODMAPs stands for fermentable oligosaccharides (fructans, galactans), disaccharides (lactose), monosaccharides (fructose), and polyols (sugar alcohols). These are found in a wide range of common foods, including wheat, cow’s milk, honey, apples, legumes, onion, garlic, broccoli and certain artificial sweeteners.

People sensitive to FODMAPs can avoid symptoms by following a diet low in FODMAP foods. Rather than cutting them out completely, the idea is to recognise the foods that are high in them and not have too many within each meal.

For people with sensitivity to FODMAPs, experimentation will show the threshold that they can eat before symptoms occur.

A typical day

• Breakfast: Fruit-free muesli with lactose free milk
• Lunch: Gluten-free sandwich with chicken, cucumber, carrot, and lettuce
• Dinner: Garlic and onion-free bolognese with gluten-free pasta
• Snacks: Nuts, lactose-free yoghurt, a banana

Does it work?

A low-FODMAP diet won’t help everyone with uncomfortable gut symptoms, but it can be a revelation for others, including some people previously diagnosed with Irritable Bowel Syndrome (IBS).

For breast-feeding women sensitive to FODMAPs, a low-FODMAP diet may reduce colic symptoms in their babies, according to new research.

There is no need to cut out entire food groups as there are both high- and low-FODMAP foods in each group.

It can be difficult to work out all of the sources of FODMAPs in your diet without getting professional help.

Our expert advice

This is an exciting breakthrough for assisting many people who suffer IBS symptoms. But be aware that removing food groups from our diet without knowing how to replace important nutrients can be dangerous, so it’s a good idea to consult an expert, such as an Accredited Practising Dietitian beforehand.

Click here for more information on FODMAPs.

Gluten-free

Avoiding wheat and other foods containing gluten

The popularity of a gluten-free diet has skyrocketed over the past year as celebrities latch onto this as a weight-loss method.

Coeliac disease is a condition where a person is unable to process gluten. When they do eat gluten, it damages the lining of the gut. It’s increasingly common. It can cause bloating, nausea, wind, diarrhoea or have no immediate symptoms at all.

A diet free from gluten is the only treatment for coeliac disease.

A typical day

• Breakfast: Rice porridge
• Lunch: Chicken and salad sandwich with gluten-free bread
• Dinner: Baked potato, steak and vegies
• Snacks: Corn Thins, yoghurt, flourless chocolate cake

Does it work?

Gluten-free eating does work for anyone who has coeliac disease. It prevents damage to the lining of the gut and allows for proper absorption of nutrients from food.

A gluten-free diet may also help those who are intolerant to wheat to reduce their IBS-like symptoms.

Despite the hype, gluten-free does not always mean it will be a  healthier option and will not necessarily help with weight loss. Often gluten-free foods, such as snack bars, biscuits, crackers and pastry are lower in filling fibre and just as high in kilojoules, fat and salt as the regular versions.

A gluten-free diet actually restricts choice so eating a healthy balanced diet may be more difficult, meaning you may miss out on vital nutrients such as iron and B vitamins found in breads and cereals.

Our expert advice

We don’t recommend this diet unless you have been diagnosed with coeliac disease or a wheat intolerance. Gluten-free is not necessarily healthier. In addition, eliminating all gluten from your diet can create nutrient deficiencies if the diet is not properly administered by a health professional.

Sugar-free diet

Giving up foods containing fructose

Fans of this diet maintain different kinds of sugars impact your body’s health in different ways. While glucose is okay under this diet, it’s fructose that’s the enemy, as it is thought to be transformed straight into fat. Fructose is found in fruit, in table sugar and the many processed foods that contain added sugar, so the aim is to give these up.

A typical day

• Breakfast: Porridge with cinnamon and slivered almonds
• Lunch: Feta and bean salad
• Dinner: Quinoa and chicken pilaf
• Snacks: Coconut water popsicle, homemade sugar-free chocolate

Does it work?

Many of us would benefit from cutting down on sugary foods. Because sugar is often combined with fat, cutting sugar means eliminating many high-fat, kilojoule-dense foods such as cakes, biscuits and pastries along with soft drinks. Many people would lose weight this way.

While sugar doesn’t cause insulin resistance or type 2 diabetes, consuming high-fat or high-sugar foods contributes to weight gain which is a major risk factor for these.

The scientific evidence that fructose is making us fat is not solid.

Cutting all sugar from the diet is restrictive, difficult to do and, like all restrictive diets, carries the danger that it could lead to an unhealthy relationship with food.

Cutting out whole foods groups such as fruit and dairy may lead to deficiencies in certain crucial nutrients.

Our expert advice

Sugar is not a problem when eaten in moderation as part of a healthy diet.

We agree that eating fewer processed, sugar-laden foods and drinks is good for many of us, simply because it would reduce the amount of hollow kilojoules we eat, but cutting it out altogether is unnecessary, extreme and something we don’t recommend.

Low-GI

Seeking out sustained energy

The Glycaemic Index (GI) measures how quickly carbohydrates are digested, on a score of 1–100. Foods with a high GI raise blood sugar levels quickly, causing a rush of energy, which then drops away. Those with a low GI (under 55) hit the blood stream more slowly, causing a sustained trickle of energy. Stable blood sugar levels give us better concentration, lasting energy and improved long-term health. They also keep us feel fuller for longer, which can help us manage our weight.

A typical day

• Breakfast: Natural muesli
• Lunch: Multigrain sandwich
• Dinner: Sweet potato mash, steak and green vegies
• Snacks: Fruit, yoghurt, a high-fibre muesli bar

Does it work?

Many studies support a low-GI diet. In particular, it has been found to help reduce your risk of heart disease and type 2 diabetes.

The largest study ever conducted into weight loss found a lower GI, high protein diet was the most successful way to manage your weight.

Food preparation and cooking techniques alter the GI of foods and peoples’ glycaemic response to foods can vary, so the GI number should be considered a rough guide.

GI is not the full story, chocolate is low-GI (because it’s also high in fat, which digests slowly), but no-one is suggesting eating more is good for us. So you still need to consider the food as a whole before tucking in. Pasta is low-GI, but eating a huge bowl of it will still push your blood sugar up so quantity is important as well as quality.

Our expert advice

The evidence does support eating a lower GI diet for good health. But rather than memorising the GI of all your meals, it’s better to think in terms of choosing lower-GI carbohydrates more often. As a start, we can swap potatoes for sweet potato, add legumes to salads and dinners and choose wholegrain and sourdough breads instead of the white stuff.