While we all know we need to limit processed foods, and should adjust the amount of carbohydrates to training load, people often think they can eat as many vegetables and fruit as they want. There is a strong believe in the general population there is no too much of fruits and vegetables. This can’t be harmful. Well…it can.
I'm eating mostly vegetables and fruits but I'm not losing any weight
One belief is that it’s impossible to consume too many calories with your vegetables. That’s not always true. Here’s why:
Firstly, it all depends on the preparation. If you add a heavy, high fat sauce or lot’s of cheese to your vegetables, you will easily consume more calories than you would with a balanced meal consisting of carbohydrates, protein and vegetables.
Secondly, not all fruits and vegetables are calorie-free; some types (e.g. starchy vegetables) can still add significantly to the amount of carbohydrates. On rest days and easy training days they are possible alternative sources for “typical carbohydrate sources”. Corn or peas are some examples. And there are also fruits that can increase your calorie intake significantly, e.g. dried (sweetened) fruit, bananas.
But the bigger issue is that especially athletes think they can cover their increased carbohydrate and energy needs with huge servings of vegetables. This, very often, leads to insufficient energy intake.
Extremely low energy intake
When athletes build their meals around vegetables and are going through an intense training cycle, their intake will not match the required needs. In some cases athletes are not only not covering their needs, their energy intake falls below a certain threshold which will lead to health consequences, especially if the deficit is present for a prolonged time. In this context we speak of low energy availability.
Many athletes want and need to lose weight to reach their race weight. Some change the diet to a mostly fruit-and-vegetable-based meal plan which is detrimental for health. It will also affect performance. Why? Due to little intake of carbohydrates, protein and fat, we create a situation of very low energy availability and cause various deficiencies. Consequently, substrate availability, recovery processes, training adaptation and ultimately health are affected and impaired.
It’s important to highlight that not all athletes run into the issue of low energy availability on purpose. Some underestimate their daily energy and nutrient needs or overestimate their portions, others just don’t know their actual needs. Nutrition support for athletes helps right there: prevent the issue of insufficient intake.
For athletes it’s important to adhere to a balanced, nutrient dense diet but it’s also important to include calories from carbohydrates, protein and fat. They don’t make you fat, they make you stronger.
Mountjoy et al (2014) IOC consensus statement: Beyond the female athlete triad – Relative energy deficiency in sport (RED-S). DOI: 10.1136/bjsports-2014-093502
Mountjoy et al (2018) IOC consensus statement on relative energy deficiency in sport (RED-S): 2018 update. DOI: 10.1136/bjsports-2018-099193