Weighing in on fad diets

02/05/2016 Help for Parents

With rising rates of overweight and obesity, it seems that fad diets are all the rage these days, making it all too easy for kids (and their parents) to be sucked into potentially dangerous trends.

Most fad diets involve rigid rules about food exclusions or restrictions, offering a ‘quick fix’ supported by little or no scientific evidence. However, the short-term results of these diets are often difficult to sustain and can result in a range of health problems such as nausea, headaches, fatigue and nutritional deficiencies.

How to spot a fad diet

Thanks to all the media hype, celebrity endorsements and the promise of a ‘new and healthier you’, fad diets can be difficult to recognise and resist. A few typical features that you can look out for include diets that:

  • eliminate or severely restrict entire food groups or nutrients (e.g. carbohydrates);
  • encourage you to only eat specific foods or ‘special’ combinations of foods;
  • promise a ‘quick fix’ or rapid weight loss solutions;
  • contradict what science and most trusted health professionals say;
  • make claims based only on a single study or testimonials; and
  • make claims that sound too good to be true (because they probably are).

Now that you are equipped with these detective skills, let’s take a closer look at some of the common fad diets lurking around and the effects they may be having on your child’s health.

The low carb diet

A low carb diet restricts the intake of carbohydrates and replaces carb-containing foods with those higher in fat and protein. Carbohydrates are found in grain foods (e.g. bread, cereal, rice and pasta) as well as fruit, vegetables, legumes and even dairy foods. A classic example of this type of diet is the Atkins Diet.

Carbohydrates are an important source of energy for the body. Many carb-containing foods are also high in dietary fibre and essential vitamins and minerals. Drastically cutting out carb-containing foods can lead to:

  • Inadequate energy intake – carbs are the body’s preferred energy source and are particularly important for fuelling active, growing kids.
  • Vitamin and mineral deficiencies – most carb-containing foods are packed full of essential micronutrients. For example, grain foods hold many B-group vitamins, while fruit and veggies contain a host of vitamins and minerals such as vitamin C and potassium.
  • Inadequate fibre intake – fibre is important for a healthy digestive system and also keeps kids fuller for longer.
  • Potentially higher intake of saturated fats – especially if high fat foods are being used to replace reduced carb intake.

The verdict? To keep kids happy and healthy, we suggest a balanced variety of low GI, high-fibre carbohydrate foods every day.

The paleo diet

The paleolithic, or ‘paleo’, diet has become increasingly fashionable (and controversial) in recent years. It’s based on the idea that we should mimic the diet of our hunter-gatherer ancestors and encourages consumption of lean animal meat and fish, fruit, veggies, nuts and seeds while banning dairy, grains and cereals, and most processed foods.

Although following a paleo diet may increase fruit and veg consumption while reducing the amount of processed foods eaten, it is important to note that:

  • the lifestyle of the hunter-gatherers was quite different to ours today;
  • they ate wild game rather than domesticated animals; and
  • the fruit and veg we eat has evolved since then.

Sticking to a paleo diet makes it difficult for your child to meet their nutritional needs because it:

  • Cuts out entire food groups – which is the number one clue when detecting fad diets. Eliminating entire food groups – in this case grains and dairy – is unnecessary and potentially dangerous. It means that your child is missing out on important sources of energy and other key nutrients including fibre, calcium and several other vitamins and minerals.
  • Leads to decreased calcium intake – because dairy is one of the best sources of calcium, a nutrient that is particularly important during childhood and adolescence for growth and the development of healthy bones and teeth.
  • Is not suited to modern lifestyles – where kids can spend the majority of their time in front of the TV or computer screen, not hunting for food.

The verdict? Kids need a balanced diet including grains and dairy to keep them healthy and energised. Try to choose whole grain cereal foods and reduced fat milk (for kids over the age of 2).

The sugar-free diet

Diets that involve ‘quitting sugar’ claim that sugar is the enemy and the cause of all sorts of health problems. These diets encourage the exclusion of all foods containing added sugars as well as natural sugars found in fruit and honey.

Quitting sugar may sound like a great idea for your kid, but the removal of sugar-containing foods also cuts out other nutritious substances unnecessarily. Remember that:

  • Nutritional deficiencies are rife with fad diets – because restricting any food group limits the intake of key nutrients that are important for your child’s health and wellbeing.
  • Not all sugar foods are created equal – so eating fewer foods with refined sugar is a good thing, but leaving out fruit and dairy products, both of which contain substantial amounts of sugar, are also fantastic sources of vitamins and minerals and, in the case of fruit, dietary fibre.

The verdict? Healthy Kids recommend limiting the amount of processed foods with added sugar (such as confectionery), but to stick to eating the recommended daily intake of fruit and dairy. Remember to choose fresh fruit over fruit juice where possible.

The low fat diet

With all the bad press surrounding fat over the past few decades, this is probably one of the more popular fad diets out there. Low fat diets restrict the amount of fat that is eaten, usually with the intent to lose weight.

But there are different types of fats, with some being healthier than others.

  • Saturated fat – the main culprit behind low fat diets, these ‘unhealthy’ fats contribute to high cholesterol and risk of heart disease.
  • Unsaturated fat – this is an important part of a healthy diet and helps to reduce cholesterol levels and lower the risk of heart disease. There are two types: mono- and poly-unsaturated fats.

It’s good to reduce the amount of saturated fat your kids are eating, but fats are still an essential part of our diet.

  • Fat soluble vitamins – otherwise known as vitamins A, D, E and K and, as the name would suggest, they require fat before they can be absorbed to carry out their functions.
  • Essential fatty acids – omega-3 and omega-6 fatty acids play an important role in the body (e.g. part of cell membranes, inflammatory responses) but cannot be made by the body and must be sourced from dietary fats.
  • Excess refined carbs – low fat diets can be more harmful than helpful if fats are simply being replaced with high carb, sugary foods.

The verdict? Fats should be included as part of your child’s balanced diet. Reduce their saturated fat intake by switching to mono- and poly-unsaturated fats. This means swapping full fat dairy for reduced or low fat products and encouraging the consumption of oily fish (e.g. salmon).

Detox diets

Detox diets claim to flush out toxins from the body by removing so-called ‘toxic’ foods from the diet, usually over a short period of time. This may involve chomping only on raw veggies, drinking juices or eliminating entire food groups. But there is no scientific evidence to suggest that these are effective. Our bodies are already built to remove and neutralise any toxic substances in food – that’s the job of our kidney, liver and immune system!

Detox diets mean that your child may:

  • Have inadequate energy intake for their needs – because most detox or cleanse diets involve some form of fasting or caloric restriction, your child probably won’t get the energy they need to run around at playtime or concentrate during class.
  • Suffer from nutritional deficiencies – depending on the type of detox.

The verdict? Detox diets are usually expensive and ineffective. Eating a balanced diet with plenty of fruit, veg, whole grain foods and water is the best way for kids to feel healthy and revitalised.

Meal replacement diets

Meal replacement diets are just that – designed to provide usually one or two meals with a low kilojoule/calorie replacement product (e.g. soup, shakes, snack bars) with the aim of rapid weight loss.

These are especially dangerous diets for kids because they can lead to:

  • Inadequate energy intake – if you child is unnecessarily restricting their energy intake, they’re likely to feel exhausted and have difficulty concentrating.
  • Nutritional deficiencies – restricting the amount and types of foods eaten greatly increases the risk of your child missing out on key nutrients (e.g. protein, vitamins, minerals etc.).
  • Reduced social eating – eating is a fantastic social activity that allows kids to interact and learn healthy habits from each other. Skipping meals or substituting them for unsatisfying alternatives can take the joy out of food and affect food choices in the future.

The verdict? Meal replacement products are often very pricey, so why not save the cash and invest in your child’s health instead? We recommend small, regular meals; three main meals and two to three snacks as a good place to start.

The bottom line

Fad diets are usually just moneymaking schemes that only work in the short-term and can be detrimental to your child’s health and wellbeing. As always, the key to a good, healthy diet for both you and your kids is balance and variety, in combination with physical activity.

Note: For some medical conditions, a specialised eating plan similar to the above diets may be necessary. In these cases, you should speak to your GP or an Accredited Practising Dietitian for more information and careful guidance.