Truth vs fiction - health myths busted

There are things you can assume about your GP: they will have illegible handwriting and will be able to discuss the weather while simultaneously sliding a needle into your arm.

But, according to doctor’s bible Australian Family Physician, you can’t always bet on them knowing the best ways to lose weight.

“There’s a great deal of misunderstanding about weight loss among health professionals,” says Dr Garry Egger, Adjunct Professor of Health and Applied Sciences at Southern Cross University (he also founded GutBusters – the highly successful “waist-loss” program for men, and the Professor Trim’s Weight Loss for Men program).

In 2008, Dr Egger gave a true-or-false weight-management questionnaire to 173 GPs and 129 tradesmen and truck drivers. “We found doctors were almost as confused as the general public,” he says. But the blame can’t all be laid at your GP’s surgery door.

“Research into nutrition, exercise and weight management is relatively new, and getting clear answers can be difficult,” Dr Egger explains. Add to that the flurry of new diets each year. It’s little wonder that many of us are left scratching our heads. Here, the answers to the questionnaire:

Fruit juice is about as fattening as beer: True

In terms of kilojoule content, equivalent servings of fruit juice and beer are roughly similar. However, as alcohol can’t be stored in the body, and is never directly converted to fat, any fattening effect is dependent on other factors, such as accompanying energy intake. The often quoted “beer belly” is therefore really more of a “beer plus food and drink” or “beer plus total energy” belly. Fruit juice is therefore potentially as fattening as beer in equivalent amounts.

We need eight glasses of water per day: False

Physiologist Dr Heinz Valtin attempted to track the basis of this belief, which he claims may be responsible for the current excessive intake of high-kilojoule drinks in the modern diet. Dr Valtin showed fluid needs are dependent on a range of factors, including age, gender, climate, activity level and disease state, and vary from 500ml (about three glasses) to 4L (24 glasses) per day. Despite the popularity of the eight glasses “rule”, international guidelines on fluid intake, now under development, suggest it’s arbitrary and meaningless.

Chocolate is healthy –provided it’s dark: False

Since the antioxidant effects of cocoa were discovered, there has been more than a decade of research on the health benefits of dark chocolate. Cocoa is high in bitter-tasting flavonoids, which are the prime source of such antioxidants, but which chocolate manufacturers extract for taste.

However, there are no labelling law requirements to inform the consumer of this. Sugar, which can lessen the benefits of cocoa, is also often added to improve palatability. So while genuine dark chocolate has health benefits, chocolate that is simply labelled “dark” does not necessarily have these benefits.

A low-protein diet is best for weight loss: False

The success of a weight-loss diet depends mainly on the total kilojoules consumed. Specific nutrients generally make little difference but some do have advantages. Protein can increase the sensation of fullness, particularly in comparison to sugary, starchy carbohydrate foods. In the context of the modern high-kilojoule diet, a reasonable intake of protein is likely to be better for weight loss than a low-protein diet.

The Federal Department of Health and Ageing’s current protein intake guidelines say around 13 to 15 per cent of total kilojoules is well below the estimated 25 to 30 per cent often proposed for weight loss and a healthy, balanced diet.

Fat people don’t get hungrier than lean people: True

It’s difficult to equate a subjective feeling, such as hunger, among individuals, but research indicates that hunger is not a distinguishing factor in obesity. Most overeating problems have a psychological and environmental rather than physiological basis, and so there is little reason to believe in a difference in genuine hunger – as distinct from psychologically conditioned “appetite” – between slim and overweight people.

Obese people can be fit and healthy: True

While fitness and fatness are usually inversely linked, several studies have shown that many active individuals can still maintain good health, irrespective of their actual body weight. There is also accumulating evidence that a significant proportion of obese people do not suffer the damaging metabolic effects from their extra weight that might be expected – while a significant proportion of their slimmer counterparts do suffer from such health problems. This has led to new questions in the research about the effects of obesity as a marker, rather than a cause, of disease.

Exercise is better than dieting for weight loss: False

It is easier to reduce energy intake by a given amount than to increase energy expenditure by the same amount. Reducing intake by 4200kJ a day, for example, is the equivalent of walking an extra 15km daily. For this reason, dieting is more likely to be successful in the early stages of a weight-loss program. But exercise is important in weight loss and may be more important than dieting in maintenance after effective weight loss. Both psychological and physiological factors must be considered, so neither exercise or weight loss are “better”.

Swimming is better than walking for weight loss: False

In general, the best exercises for weight loss are those that are weight bearing, such as walking or jogging. Up to 30 per cent less energy is used in activities such as swimming or cycling, which support weight and can be carried out at a more leisurely rate. Because fat floats, an obese person is likely to use relatively less energy while swimming, particularly if they are an experienced swimmer. This doesn’t negate the benefits of swimming as an exercise, but reduces its relative effectiveness for fat loss compared with walking.

Weightlifting is good for fat loss: True

In general, any form of exercise involving energy expenditure has benefit for weight loss. Resistance training is often underrated and considered only for the development of strength or size. However, where large muscles or muscle groups are used – or in resistance training using light weights at high repetitions – weightlifting can be effective for weight loss as well as for strengthening muscle.

The best measure of body fat is your Body Mass Index (BMI): False

Body Mass Index (BMI) – a ratio of a person’s weight to their height – does not correlate well with fatness in individuals. BMI is often found to be less accurate in people who have a more muscular body type, some ethnic groups such as Pacific Islanders, and elderly people, whose height shrinks with age. Using BMI as a measure of body fat can lead to people developing unrealistic weight goals. Waist circumference is a far better estimate of an individual’s body fat.

You lose more weight doing exercise you are good at: False

Individuals become more efficient and therefore expend less energy as they gain experience with a particular form of exercise. For example, a fit, experienced runner requires less energy to cover a set distance than an unfit individual would who’s the same weight, age and gender. Weight loss requires excess energy expenditure, which comes more from activities that we’re not so familiar with.

Dairy products can help with weight loss: True

The accuracy of this statement remains controversial. Because of the fat content of most natural dairy products, a common belief exists that all dairy products cause weight gain. But recent research – both across communities and in dietary experiments with individuals – suggests eating low-fat dairy is linked to weight loss. There are indications that certain dairy ingredients, such as whey protein and combinations like protein and calcium, can increase feelings of fullness, and increase the kJs lost when you poo, both of which may help weight loss.