Busted! 3 sports nutrition experts tackle 3 food-and-exercise myths | UniSC | University of the Sunshine Coast, Queensland, Australia

Should you eat meat to beat the elite in sport? Will you lose more weight if you exercise before breakfast? Does magnesium help you sleep more soundly after training? 

Three University of the Sunshine Coast sports dietitians tackle three popular beliefs among people wanting to improve their fitness or sporting goals. 

Clinical educator Zara Nance, Professor Gary Slater and lecturer Dr Amy-Lee Bowler have decades of experience in advising athletes at the top of their game, working with state and national organisations across sports from rugby league to swimming to skateboarding. 

They hope their latest research sheds light on the facts, to help amateur and professional sportspeople better inform their health and fitness. 

What exactly is it? 

The carnivore diet is typically the consumption of anything animal-based, such as all types of red meats, chicken, eggs, seafood, fish. Some may consume different types of dairy products as well. The dietary approach excludes all vegetables, fruits, starches and grains, legumes, seeds and nuts. It is essentially touted as a “zero carbohydrate” diet. 

So, what’s the truth?  

The reality is a carnivore diet is a restrictive dietary approach that may be harmful to long-term health and jeopardise performance and athletic ability. Here’s why: 

• Low carbohydrate: Not including a variety of carbohydrates into an athlete’s diet will underfuel and provide the incorrect type of energy for the work required. Eating low carbohydrate often results in fast water weight-loss, as each gram of carbohydrate is stored in human muscle with at least three grams of water.  
• Low fibre: The diet does not provide any source of fibre, which may cause uncomfortable gut symptoms and long-term implications. A diet low in plant diversity leads to a less diverse gut microbiome, which can contribute to chronic inflammation and other health issues.   
• High in protein: Excessive protein displaces other nutrients, vitamins and minerals that may affect immune health, bone health, gut health and overall energy.  
• High in saturated fats: In large quantities, these fats can promote weight gain and inflammation. They also negatively influence cholesterol markers and heart health. 
• Social and practical challenges: The diet’s restrictive nature diet can be difficult to sustain socially, financially and nutritionally over the long term. 

Overall, the carnivore diet is not healthy or sustainable for an athlete or anyone to follow.

Online personalities promoting this way of eating often rely on anecdotal evidence, cherry-pick data and use fear-mongering narratives and false claims, despite strong scientific evidence to the contrary.

It is possible they have financial incentives, such as selling supplements, online coaching or programs. A critical approach is needed to separate real health advice from misinformation. 

MYTH 2: Train fasted (before eating) in the morning to promote fat loss

With Professor Gary Slater, AIS Nutrition Lead and UniSC Lecturer (Master of Sports Dietetics)

We’ve all heard it before – exercising on an empty stomach supports fat loss. In reality, there is little research to support this claim. Sure, fasted exercise results in a slightly greater use of fat as a fuel, but this has little, if any, impact on fat loss. Other factors should influence your decision to eat or not prior to a morning exercise session. They are:

How long is the session?

Additional fuel is generally encouraged for sessions of 60 minutes or longer. For shorter sessions, it can be fine to just get the training done. For longer sessions, take the time to refuel the body after a long night.

How hard is the session?

Intense training may leave some individuals feeling sick, preferring to eat after training. A snack may not be needed for shorter, intense sessions, but for longer, harder sessions, try grabbing a liquid snack like a juice or smoothie to fuel your body. Liquids tend to be better tolerated as they leave the stomach quicker.

Remember that food is fuel and the better you fuel your body, the better the response from training.

MYTH 3: Magnesium supplements are the answer to better recovery and sleep

Dr Amy Bowler, QAS Swimming Dietitian and UniSC Lecturer (Master of Sports Dietetics)

From improved recovery post-exercise to better sleep quality, magnesium supplementation has been touted as a non-negotiable for athletes wanting to optimise overall health and performance. While its use has grown exponentially among athletes, the evidence to support magnesium as a sleep and recovery booster in athletes is lacking.

So, why are there so many believers out there? 

Previous research has been conducted in older adults and pregnant women (populations at greater risk of magnesium deficiencies), with some studies demonstrating a sleep and/or recovery benefit associated with magnesium supplementation. Interestingly, there have been no published studies supporting a recovery benefit or reduction in exercise-induced muscle cramp among athletic groups. The same rings true for sleep – no published literature has demonstrated a beneficial effect of magnesium on the sleep quality of athletes. 

What can athletes do to aid in recovery and sleep?  

If seeking nutrition to aid in recovery and sleep quality, athletes can focus on evidence-based recovery strategies. These include consuming food rich in quality carbohydrates to refuel muscle stores, lean protein to aid in muscle repair, and fluids and electrolytes to promote rehydration post-exercise. Some excellent recovery options that require minimal preparation are flavoured milk, fruit yoghurt with muesli, and smoothies. To further aid sleep quality, athletes should ensure sufficient intake of whole foods and fluids across the day and be mindful of drinking caffeine around bedtime.