"Energy drinks are a very effective thing!", emphasised nutritional scientist Paolo Colombani from Nutritional Biology ETH Zurich (3) in his crash course for athletes and their coaches. In a two-hour session on the evening before the actual meeting Colombani and his colleague Christof Mannhart presented the main points of their latest research in a relevant and entertaining presentation. A short introduction of the scientific facts was followed by suggestions for their possible application in optimal diets for top athletes.

Organiser Paolo Colombani: "Human beings were built to move." large

Lots from the bottom, little from the top

Organiser Colombani opened the meeting with an overview of the revised Swiss Nutritional Pyramid (to be published next month). Its aim is to provide society at large with an intelligible guide to help them make healthy nutritional choices. It does not so much differentiate between "good" and "bad" food as give clear recommendations on quantity–in keeping with a citation from Paracelsus: "All things are poison and nothing is without poison; it is the dose that makes things poisonours." So while fruit and vegetables–of which five daily portions should be eaten–build the basis of the pyramid, products containing sugar are at the top of the pyramid and should be consumed in only small quantities.

The current version of the Swiss Nutritional Pyramid (see picture above right) was developed in 1998 and was an improvement on the original US version because it included drinks on the bottom–most important–level of the pyramid. Now, after seven years, substantial changes have been made to this level: instead of "1.5 litres of liquid" the recommendation is now "to drink between 1 and 2 litres per day". Colombani explains the reason for this change by citing a further maxim from Paracelsus: Everything has its upper limits–even water. In addition, alcoholic drinks have been moved to the top level of the pyramid, because as far as alcohol outside meals is concerned Colombani says: "Every quantity is too high".

"Energy drinks are very effective things," explains Paolo Colombani in his talk and participants were able to judge for themselves during the break. large

Nuts instead of crisps and cola

Another change at the top of the pyramid is the entry of sugar sweetened drinks and salty snacks. While crisps and cola should only be consumed in moderation, fatty foods are more prominent at a lower level–because the recommended quantity of carbohydrates has been reduced. Another notable novelty is the recommendation of nuts which, consumed in moderation, are now believed to reduce the risk of cardiovascular diseases.

The old nutritional pyramid: A lot from the bottom, a little from the top. (Picture: Swiss Society for Nutrition) large

Athletes don't eat enough carbohydrates

Starchy foodstuffs are to be found in the middle of the pyramid, to which pulses have now also been added. Nonetheless, Colombani finds the official daily recommendation for carbohydrates too high, especially for physically inactive people. For athletes, on the other hand, the opposite is true. Owing to their high level of physical activity athletes' energy stores should be filled with sufficient quantities of carbohydrates on a daily basis. Already a study carried out two years ago showed that 53 per cent of male athletes and 67 per cent of female athletes did not consume enough carbohydrates (4). Colombani has extended the levels of the nutritional pyramid–to the right and to the left–for athletes, taking into account daily hours and intensity of their training. The composition of athletes' basic nutritional needs was not fundamentally different from that of other people, Colombani said, physically active people just needed more.

Highly refined carbohydrates were the focus of attention several times during the meeting: disparaged on the one hand as a main cause of overweight and diabetes, praised on the other as an effective performance enhancers to athletes. Trials have shown that even the simple rinsing of the mouth with energy drinks can considerably improve performance, even when it is not swallowed. Researchers think it likely that this is caused by neuronal effects.

Idleness leads to illness

The decisive factor for good health was to be found outside the pyramid. Because without sufficient physical exercise it is difficult to remain in good health even with an optimal diet. Colombani adds, "Physical inactivity is a form of illness." The energy balance is central to the metabolism. Our lifestyles today, however, usually lack the level of physical activity to which our metabolism has been attuned by evolution over millions of years (5). In former ages cycles of plenty alternated with cycles of hunger. In order to feast and replenish his energy reserves a hunter had to work with his muscles. Hunger forced people to be physically active. This cycle is interrupted in a number of places today. The muscles are slack but the energy stores are filled anyway.

Big crowd: the main lecture was filled with around 300 participants. large

Lack of exercise, not fast-food

The main cause of the huge increase in the numbers of overweight people and the rise of associated illnesses and conditions in today's affluent society was not due to the excessive consumption of fast-food but lack of exercise, confirmed Fred Brouns from the Netherlands in his presentation on carbohydrates. A cyclist competing in the Tour de France consumed about a kilo of highly refined sugar a day in the form of energy drinks and concentrated energy snacks without negative effects on his health.

Iron in sports–a hot potato

German Clénin from the Scientific Sports Institute in Magglingen presented various case studies to show that, in cases of iron deficiency, iron supplements are a sensible option. Amongst top athletes and their trainers, however, this is still controversial because of disagreeable secondary effects, such as diarrhoea, nausea or constipation.

The new nutritional pyramid, to be published next month by the Swiss Society for Nutrition (SGE (6)), will also be the basis of an optimal diet for athletes. Colombani and his team are working on an adaptation of the pyramid to meet the special needs of athletes, which will appear sometime this summer. "ETH Life" will be reporting.