Wednesday, April 7, 2010


Popular 'low carb' diet overhauled

Fad diets come and go and some are revisited, but yet they always seem to be an ongoing topic of conversation in the media and even amongst friends. The Atkins diet is back and revamped with the inclusion of fruit and vegetables. Wholegrains are introduced in the maintenance phase. Why has this diet been changed if it was, in its original form, an appropriate and successful method for weight loss? Can it be that event the proponents realise there is a better way?

The word 'diet' is a head turning top, but for most dietitians and nutrition healthcare professionals, it can have an eye rolling effect. The term 'diet' - once used to describe the usual food and drink intake of a person - is now more commonly associated with a restrictive regimen to promote weight loss.

There are countless diets that claim effective and quick weight loss, most often not supported by research. Weight loss trademarks claiming 'sweet, sexy, science' are related more to marketing than to credible research. What can be sweet and sexy about a weight loss program even though it claims to have the science behind it? Science in simple terms is knowledge gained through research and investigation.

Our ancestors seemed to live a simple life, food was consumed closest to its natural form, technology was not as evolved, people were more active and overweight and obesity was not common. Today the incidence of overweight and obesity is of concern. In 2007-08, one quarter of all Australian children aged 15-17 years were overweight or obese. Studies have shown that once children become obese they are more likely to stay obese into adulthood and have an increased risk of developing chronic diseases. In 2007-08, almost two-fifths (37%) of adults in Australia aged 18 years or over, were overweight and a further quarter (25%) were obese. The economic cost of obesity due to the loss of wellbeing and burden of disease is enormous ($8.3 billion in 2008, in Australia).

The World Health Organisation projects that by 2015, approximately 2.3 billion adults will be overweight and more than 700 million will be obese, globally. With these fast growing statistics it is no wonder that organisation are claiming to have the solution to weight problems.

The simple laws of physics demand that energy 'in' should equal energy 'out'. However, our increasingly sedentary lifestyle at work and home, modes of transportation and increased intakes of energy dense foods (high in fat and sugar but low in vitamin, minerals and other nutrients), means the modern trend is for a higher energy intake than expended by the body.

Surely a lifestyle change is necessary to ensure energy consumed does not exceed expended, rather than a diet that claims to kick start weight loss by restricting carbohydrates? Even the term 'kick start' mentions physical activity! As well as monitoring food intake, physical activity should be a focus of healthy weight management.

Diets that are focused on restricting carbohydrates (commonly referred to as carbs) - some even go to the extent of providing carb counters - should send off warning bells. Who wants to count numbers around everything eaten? Weight management is not simply about limiting energy by restricting carbohydrate intake - because everything contributes energy, particularly fat and protein - but more about quality and quantity eaten.

Diets that severely restrict carbohydrates often recommend eating meat such as bacon on a regular basis and clearly do not have the correct science behind them. For example, a piece of bacon is nutritionally inferior to a slice of wholegrain bread or an apple - high quality carbohydrate foods that provide nutrients, antioxidants and fibre. What is important is the quality of carbohydrate eaten. Fruit, breads, cereals (particularly wholegrain) and legumes are carbohydrate containing foods that should be included in a healthy diet every day, whereas carbohydrate foods such as ice cream, soft drinks and sweet biscuits should be treated as 'occasional' foods.

Food is not only eaten to provide sustenance, it also provides enjoyment, and often brings family and friends together. So too does exercise (gold, soccer, football, walking). Remembering the simple rule of physics ensures we can enjoy eating a variety of food and drink in moderation each day, whilst being physically active. Maintaining this long term contributes to a healthy lifestyle.

2. Australian Bureau of Statistics, 2009. Australian Social Trends. Commonwealth of Australia
3. World Health Organisation, 2006. Fact Sheet 311: Obesity and overweight

Recovery from exercise

Switch your sports drink for cereal & milk

You have just returned home from a long bike ride or run, do you reach for the big brand sports drink or sit down to a nutritious bowl of wholegrain cereal and milk? The results from a recent study in the US could change your mind and improve your bank balance. The researchers found the readily available and cost effective recovery option of cereal and low fat milk was comparable to sports drinks in refuelling muscles with glycogen, and may be better at helping tired muscles build protein.

Originally designed to offset dehydration in elite athletes, sports drinks are marketed strongly and have high product awareness amongst the general public and elite athletes. They contain sodium, potassium and chloride plus around 6% carbohydrates and are formulated to aid rapid recovery by providing energy for active muscles and electrolytes for re-hydration. Available in an endless range of flavours to suit individual preferences, sports drinks may help to encourage drinking and re-hydration through their preferred taste compared to water.

Lynne Kammer and her team of researchers at the University of Texas at Austin set out to research the effect of using ordinary foods after moderate exercise (as performed by an average fit individual) to support recovery processes. Endurance exercising causes short term changes to occur in the body, particularly in the muscle. Energy stores are depleted and muscle proteins are broken down to make way for new, stronger muscle proteins. Optimal recovery of muscle energy stores and muscle repair requires eating the right foods at the right times.

The researchers fed 12 healthy trained subjects with either 1200mL of sports drink or 73g (about 1 1/3 cups) of wholegrain cereal and 350mL of skim milk after 2 hours of moderate cycling (60-65% VO2Max). They found no significant differences between sports drink and cereal and milk, except for one marker of protein synthesis. The results of this study suggest that wholegrain cereal and milk is as good, and in some aspects may be better than, commercially available sports drink at kick starting muscle recovery after exercise, especially when refuelling at home, where cereal and milk is often freely available.

The important take home message from this study is not only that ordinary whole food sources such as cereal and milk may offer a more cost effective recovery strategy than commercial sports nutrition products, but also that the combination of protein and carbohydrate from whole foods provide an easily digestible, high quality source of protein and carbohydrates with naturally occurring nutrients, as compared to extra calories provided from a somewhat expensive sports drink. Other protein-carbohydrate recovery foods might include low-fat yoghurt and fruit, low-fat flavoured milk/smoothie or a sandwich with meat/cheese.

Kammer et al, Cereal and nonfat milk support muscle recovery following exercise. J Int Soc Sports Nutr, 2009, 6:11