Carbohydrates: good for you!

Since the Atkins Diet appeared on the scene in South Africa, carbohydrates have become increasingly unpopular. But the new South African Guidelines for Healthy Eating has put carbohydrates back where they belong: at the foundation of a healthy diet. ELMIEN WOLVAARDT reports.

Remember the food pyramid? This (somewhat old-fashioned) nutritional teaching tool showed the different food types and the proportions in which they should be eaten. It placed starchy foods - which are rich in carbohydrates - at the base, implying that they should form the main part of all meals. Vegetables and fruit came next, followed by meat and dairy in even smaller amounts, with sugars and fats forming the smallest component of a healthy diet.

But with the promotion of high-protein, low-carbohydrate diets such as the Atkins diet, carbohydrates seemed to have fallen by the wayside.

Although these diets all claim that they are based on the latest nutrition research, scientists at the South African Medical Research Council (MRC) strongly disagree.

'These diets are essentially nothing new. They've been coming and going since the Sixties, and just get re-packaged every time around,' says Dr Lesley Bourne, a dietician in the MRC's Health and Development Research Unit.

'None of the claims made by low-carbohydrate diets have changed the basics of good nutrition, which are based on the best currently available scientific evidence. And according to this evidence, unrefined starchy foods should be eaten in larger amounts than any other foods.'

'Make starchy foods the basis of most meals,' is just one of the eleven guidelines contained in the South African guidelines for healthy eating, released last year, which has been officially endorsed by the South African Department of Health.

Since 1997, Dr Lesley Bourne and Dr Petro Wolmarans (from the MRC Nutritional Intervention Research Unit) were members of the Food Based Dietary Guideline working group, which was responsible for formulating these guidelines for South Africa. Dr Nelia Steyn, also of the MRC (in the Chronic Diseases of Lifestyle Research Unit), formulated the guideline for sugar intake which also forms part of the guidelines.

Prof Esté Vorster of the University of North West, was commissioned by the Nutrition Society of South Africa to initiate this project. The Association of Dietetics in South Africa also became partners.

'Most South Africans base their meals around meat, but the South African guidelines for healthy eating suggests that South Africans should make starchy foods the basis of most meals,' says Prof Vorster.

'This means choosing the unrefined starchy food you want to have for dinner - such as brown/ whole-wheat bread, brown rice, unrefined maize meal, couscous, potatoes or pasta - and building your meal around that, which means adding plenty of vegetables, legumes, some dairy and/ or a smaller portion of fish, meat or eggs,' she says.

But, aren't carbohydrates a no-no if you want to lose weight?

'It is true that too much of anything can cause you to gain weight, so moderation is still the key. However, just as important is eating the right kinds of carbohydrates,' says Ms Whadiah Talip, a dietician doing her Master's degree within the MRC.

'Unrefined starchy foods such as whole-wheat bread and brown rice are better: they contain more vitamins and minerals, and also make you feel full for longer - which prevents over-eating,' she says.

In fact, unrefined starchy foods are full of B-vitamins, which play an important role in keeping the body's metabolism - its calorie-burning machines - going strong, according to Dr Bourne. 'B-vitamins drive the engine of metabolism - if you're low in these vitamins your metabolism slows down and you use up fewer calories - with the excess calories piling up as fat.

'It is important to keep in mind, though, that carbohydrates by themselves taste quite bland. We tend to combine them with other ingredients, such as sauces and meat, which can be full of hidden fats - the real culprits in weight gain,' Dr Bourne says.

'It isn't the pasta or rice that makes you fat,' confirms Ms Talip, who is involved in the promotion of these guidelines to doctors and other health practitioners, 'it's what you add to them. Use tomato-based rather than cream-based pasta sauces, and use fat-free milk rather than full-cream milk or cream when making white sauce.'

However, not all fats are the same, Dr Petro Wolmarans points out: 'Although it is important to eat fats sparingly, as stated in the guidelines, it is difficult - not to mention unhealthy - to eliminate fats completely.

The body needs some essential fatty acids that cannot be formed in the body.

'Good sources of these fats are for example sunflower oil, fatty fish and certain nuts. You can minimise the impact on your heart and arteries by limiting animal fats and choosing vegetable oils such as olive oil, sunflower oil and soft margarine (without trans-fatty acids) instead. But still use them sparingly.'

'The problem with a high-protein, low-carbohydrate diet is that it tends to increase the amount of animal fat in your diet, which can cause cardiovascular problems,' says Prof Vorster.

'In the long run, the evidence shows that nothing beats a diet based around unrefined carbohydrates, plenty of vegetables and fruit,' she says.

Designing the guidelines
Before the South African guidelines for healthy eating was produced, nutritionists and educators had to rely on nutrient-based, as opposed to food-based, guidelines. One example of this is: 'Not more than 30% of a person's energy must be obtained from fat', a guideline that is difficult for the public to understand, let alone follow successfully.

Prof Esté Vorster of the University of North West, Potchefstroom campus, wanted to address this shortcoming by developing food-based dietary guidelines for South Africa. 'How can you tell someone in rural South Africa to increase the amount of chromium in their diet? People eat food, not nutrients,' she says.

The first phase of the project coincided with the publication of guide lines by the World Health Organisation (WHO) and the Food and Agriculture Organisation (FAO), which suggested that each region in the world should compile their own food-based guidelines to address public health issues in the region.

In South Africa, there are two seemingly contradictory public health problems.

'Children are very vulnerable to under-nutrition - 23% of children between one and nine years old are so under-nourished that they become permanently stunted in their growth. In adults, however, we are seeing very high levels of obesity. The obesity level among African women is one of the highest in the world,' says Prof Vorster.

'Along with urbanisation, traditional diets have become increasingly Westernised, which has increased obesity and the risk of all the non-communicable diseases, from diabetes to heart disease,' says Prof Vorster.

The South African guidelines for healthy eating were designed to be understandable, affordable and culturally acceptable, and are based on indigenous foods, which is also in line with the WHO/ FAO guidelines.

'We decided to avoid telling people what they must not do. The guidelines are positive, and tell people what they can do to optimise their health, says Prof Vorster.

'We want South Africans to eat a variety of foods, and stop feeling guilty about everything they put into their mouths. Food is there to be enjoyed!' she says.

Did you know?

• Our bodies need a variety of foods - no single food or meal can provide us with all the nutrients we need.
• Soft tub margarine (without trans-fatty acids) is healthier than margarine sold in bricks, as they contain fewer hydrogenated oils (made up of trans-fatty acids), which are bad for your heart.
• Eggs are good value for money. They are a good source of protein, and you can eat them three or four times a week to replace meat or chicken. They also contain B-vitamins, which help your metabolism.
• About two cups of milk (calabash milk 'maaskaas', yoghurt or sour milk) are required per person, per day, in order to provide enough calcium. You can replace a cup of milk with 30 grams of cheese (about the size of a match box).

Improving your metabolism
Metabolism takes place chiefly in the muscle cells of the human body. Muscles contain huge concentrations of mitochondria, the tiny 'machines' that live inside these cells and convert carbohydrates into the raw energy we require to move, breathe and think. You can improve your body's ability to convert food into energy in three main ways:

1. Do weight-bearing exercise, such as walking, cycling or working with light weights. This builds more muscle tissue, which in turn will increase the overall number of mitochondria in your body, which means that you will burn more energy.
2. Ensure that your diet provides you with sufficient B-vitamins - needed to keep the mitochondria working at optimum levels. Good sources of B-vitamins are unrefined carbohydrates, eggs, liver, and green, leafy vegetables.
3. Eat smaller meals more often: between three and five per day. Eating only one or two meals per day has been shown to slow down your metabolism.