Dietary basics for athletes: will we ever learn?

Given 24/7 access to the internet and an explosion of sports nutrition knowledge – particularly relating to sport performance – this should (in theory at least) mean that most athletes have all the required tools at their fingertips for optimizing their day-to-day diet. Even when lifestyles are chaotic and planning is not a forte, the there are numerous software programmes to help design well-balanced, nutritionally complete menus, which are readily available for mere pennies or even for free. With that in mind, you might assume that in 2024, making basic mistakes with nutritional intake is a thing of the past, especially in elite/professional athletes.

But what does the recent evidence actually tell us about the nutrition habits of 21st Century athletes? Sadly, it seems that a significant number of sportsmen and women are still falling short of meeting their basic nutritional needs. As a scientific researcher and writer, I first reported on this topic for SPB back in 2010, where we demonstrated that sportsmen and women across a wide range of sports and nationalities are still vulnerable to poor nutritional habits. In particular, it seems that our growing understanding of the athlete’s nutritional needs and the easy availability of excellent online information and advice does NOT seem to have improved athletes’ levels of knowledge or diminished findings of nutritional insufficiency in the athletic community. Just a few examples of these findings include:

·        Elite male swimmers – over 50% of whom were deficient in calcium and insufficient in carbohydrate intake⁽¹⁾.

·        Female judo athletes who failed to meet their needs for iron, calcium B1 and niacin intakes⁽²⁾.

·        Female handball, runner, karate and basketball athletes, 100% of whom failed to meet their magnesium and copper intake requirements⁽³⁾.

·        Highly trained female cyclists, whose average daily intakes for folic acid, magnesium, iron, and zinc were sub optimum, while. More than one-third of the cyclists failed to consume even 60% of the recommended daily intake for vitamins B6, B12, E and the minerals magnesium, iron, and zinc⁽⁴⁾.

·        Seventy two elite female athletes where 65% failed to meet carbohydrate intake recommendations and many failed to meet their needs for for folic acid, calcium, magnesium, and iron⁽⁵⁾.

·        Over 550 Dutch elite and sub-elite athletes, the majority of whom had sub-optimum vitamin D intakes and where iron intake was sub optimum in a substantial number of the women⁽⁶⁾.

The ‘performance in a bottle’ myth

As we shall see shortly, the frequent problem of athletes consuming poor or sup-optimum day-to-day diets has not gone away. But why is the case given there’s so much information out there? One possible explanation is that many athletes mistakenly believe that high-tech sports nutrition formulations and supplements can guarantee optimum performance, leading to a ‘performance from a bottle’ mentality. Unfortunately however, relying heavily on sports nutrition products may actually lead to a poorer basic diet quality, because many athletes simply assume that they no longer need to worry about eating high quality natural foods, thereby leading to a reduced intake of key nutrients such as fiber, antioxidants and essential fats.

A poorer-quality, low-nutrient diet is undesirable for a number of reasons – not least because such diets are associated with lowered immunity and a generally reduced resilience of the body to withstand the day in, day out rigours and cumulative stresses of training. While sports drinks and supplements have their place – especially when training volumes and intensities increase – an athlete’s day-to-day diet is actually far more important, and the true cornerstone of health, vitality and resilience to withstand the demands of training. 

Female athletes and day-to-day diet

As the evidence from studies has continued to accumulate, some researchers have concluded that female athletes may be especially vulnerable when it comes to less than ideal dietary patterns and sub-optimum nutrition⁽⁷⁾. The reasons are complex, but most likely due to the different physiology of the female body – for example monthly menses, which increases the risk of iron deficiency – along with other factors such as a desire to reduce body fat levels through increased training loads, and aesthetic reasons (particularly in sports such as gymnastics and swimming where athletes are subject to the pressure of performing in front of large crowds).

Examples of the female dimension to this problem can be seen not only in the studies listed above^(2-5) but also from research suggesting that female swimmers⁽⁸⁾ and female gymnasts⁽⁹⁾ may be among the highest risk athletes for poor dietary practices in sport (for all the reasons cited above). In a 2021 study, which we reported in a previous SPB article, Slovenian researchers compared the risk of nutritional deficiencies in the two sports among age and performance-level matched female athletes (17 swimmers and 17 gymnasts) of the same age and all training and competing at a high level ⁽¹⁰⁾. As well as assessing cardiovascular health markers and body composition measures dietary intakes were analyzed using a standardized food frequency questionnaire and blood tests were carried out to determine actual nutrient levels. The key findings were (see figure 1):

·        Both groups had low intake of carbohydrates, fibre, polyunsaturated fats, and high intake of free sugars and saturated fats

·        The gymnasts were consuming low levels of protein

·        Both groups were deemed insufficient in micronutrient (vitamin and mineral) levels but the gymnasts much more markedly so (see figure 1).

·        Both groups had very significantly lower-than-recommended serum levels of vitamin D3.

Figure 1: Dietary intake of elite-level gymnasts and swimmers