Trending Diets and What Our Dietitian Has to Say About Them

It seems we are constantly inundated with diet trends promising us a world of benefits. With the mass of marketing that surrounds them, it can be hard to seperate fact from fiction. Here, our dietitian Gabrielle will run you through three popular diet trends in 2022 and help bring some clarity on them.

Low carb, high fat (LCHF) and keto diets

Keto and LCHF diets have been hanging around for years. The basis of these diets is to eat as little carbohydrates (<10% energy intake) as possible and to eat more fat to compensate (>70% energy intake). Eating this way forces the body to switch from using carbohydrate for fuel to using fat in the form of ketones, in hopes of achieving ketosis – “the optimal fat burning state.”

High fat enthusiasts make big claims - that eating low carbs leads to weight loss, improves immunity and well-being. But there is very little robust evidence to support these claims.

From a holistic health perspective, too much fat in the diet, specifically saturated fat, can contribute to a higher risk of heart disease.

Displacing carbohydrates with fats also means you are probably not eating much dietary fibre. Dietary fibre is needed to increase the diversity of your gut microbiome – by feeding the bacteria in your gut. A healthy gut microbiome is critical for reducing inflammation and oxidative stress, not just for optimal recovery, but for improved health and wellbeing (and even better mood!).

Low carb diets are also less than ideal for endurance athletes. Research has shown that developing an over reliance on fat for fuel can reduce your bodies ability to use carbohydrate efficiently. This means, your body won’t be able produce the energy it needs when you need that big push up a hill or a sprint to the finish.

The bottom line?

There is currently no evidence in favour of a ketogenic diet or low carb, high fat for exercise performance or general well-being.

For athletes who may want to “train low” to challenge their fat metabolism, working with a dietitian can help you figure out how to “train low” without compromising your overall health and performance.

Intermittent fasting

The idea behind fasted training is similar to low carb diets - to encourage the body to burn a higher percentage of energy from fat and to reduce its reliance on using glycogen (stored carbohydrate) for fuel. However, the main issue with fasted training is that without eating before training, your body simply doesn’t have the energy it needs to exercise, and so you are likely to get fatigued sooner.

The second major issue is that fasted training places stress on the body, increasing the stress hormone cortisol. Raised levels of cortisol in your body can contribute to higher risk of injury, a weakened immune system and disruptions to reproductive hormones, such as oestrogen, progesterone and testosterone. For active women, this can result in irregular periods or loss of periods. And for men, disrupted testosterone levels can result in loss of libido. Both are bright red flags for RED-S!

The bottom line?

Fasting for short periods of time or once in a while has little or no effect on the health or performance for most athletes and an overnight fast of 8-12 hours is pretty normal for the majority of people. However, fasting has been shown to have negative effects on health and performance when rigid fasting time-frames prevent you from fueling optimally before, during or after exercise.

 Plant-based diets

 Eating plant-based is becoming more mainstream, whether you decide to not eat any animal products or you take a more flexible approach.

Anecdotally, athletes report that eating plant-based increases their energy levels, helps them to recover faster, and they report that they experience less injury and fewer illnesses.

Scientifically, research has shown that plant-based diets provide a number of benefits to the body that can have performance advantages.

 -         Firstly, plant-based diets are often higher in carbohydrate, which helps to optimise glycogen stores. This improves power output and endurance, and reduces early onset of fatigue.

 -         Secondly, eating a plant-based diet also means you are probably eating more wholegrains, fruits and vegetables, legumes, nuts and seeds. This provides your body with dietary fibre, polyphenols and anti-oxidants, improving your overall health and well-being.

-         Finally, plant-based foods contain higher levels of nitrates. These are found in many vegetables, particularly green leafy vegetables and beetroot. Your body converts nitrates to nitric oxide, which helps to improve blood flow, leading to better oxygen delivery to the muscles, and ultimately aids recovery.

But what about protein?

Well, research has shown that there is no difference in muscle building or endurance between athletes who follow a plant-based diet compared to those who eat animal-based proteins.

Contrary to popular belief, plants are indeed complete sources of protein (i.e. they contain all 9 essential amino acids (EAAs)), just like animal-based proteins. Although, pulses, grains, nuts and seeds tend to contain relatively lower concentrations of one or more EAAs. On the other hand, soya products (e.g. tofu, tempeh and soy milk), quinoa, chia and hemp seeds, and buckwheat contain EAAs in ratios more closely matched to the body’s needs. Provided you eat a variety of plant-based foods, any shortfall of EAAs in one food is compensated by the higher amounts found in another. Working with a dietitian can help you ensure that you are eating enough of plant-based proteins.

The bottom line?

Studies provide compelling evidence that excluding animal products does not put you at a disadvantage when it comes to training, strength or recovery. Although there is no definitive proof that cutting out animal products will make you a better athlete, there are a number of ways it may confer a performance advantage and improve your overall health and well-being.

So what’s the magic pill when it comes to sports nutrition?

 Well, the simple answer is there is not one diet that does everything for everyone. But there are three key take-homes these diets show us:

1.      Carbohydrates are your best friend when it comes to fueling for training and performance

2.      Our bodies need the right fuel at the right times to meet our personal training programme

3.      Everyone can benefit from eating more plants 

Gabrielle Orr joined the Sports Lab team this week…Welcome Gabrielle! In a culture that presses for leanness, restriction, and good vs bad foods, Gabrielle is passionate about helping active individuals cut through the noise to determine what works best to support their training and life. Basically, she’s a fantastic dietitian that we all need in our lives.