What is intermittent fasting?

Intermittent fasting (IF) is a pattern of eating that alternates between periods of fasting, and eating. The fasts can be:

• Daily (e.g fasting for 16hours and allowing an 8 hour eating window)
• Weekly (e.g. fasting for 24hours 1-2 days per week)
• Yearly (e.g. fasting for 3-5 days once or twice a year).

These diets have a strong media presence and have been linked with many celebrities. They seem to be popular because of their simple nature.

There are typically two goals for people who fast. Either weight loss, or optimisation of health markers, with or without weight loss.

Can Intermittent fasting help with either of these goals?

Weight loss can occur simply as a result of a shorter feeding window leading to reduced calorie intake. The research that we have to date, has shown no significant differences in weight loss, blood fats concentrations, blood sugar levels and insulin levels in those who engage in continuous restriction (the type that characterises other diets), compared to IF (1, 2). * The longer term effects (beyond 12 months) of this approach remain unclear, and further research is therefore required. 

What are some of the benefits of avoiding eating before bedtime?

Late night eating is typically defined as eating past 8pm. There is some research that may support the benefits of eating the biggest calorie meal earlier in the day on blood fats, and blood sugar levels, but much of the research we have around nighttime eating is conducted in shift workers who have quite extreme patterns.

It’s important to highlight the huge amount of class privilege that comes with being able to choose the timing of eating. Some people can’t even eat consistently, because they can’t afford it.

Humans are complex, and putting time restrictions on eating is often not practical and does not allow the individual to honour their natural hunger signals. As a clinician, I encourage individuals to pursue what feels and works best for them.  

So if not intermittent fasting, what would you recommend to control weight? 

There is limited evidence to support the long-term benefits of weight loss. Whilst we know that weight loss is possible in the short term, there is overwhelming evidence that shows any form of intentional weight loss has no long-term success.

Regardless of the degree of initial weight loss seen with lifestyle intervention, most weight is regained within a 2 year period, and by 5 years the majority of people are at their pre-intervention weight. 

We’re often led to believe that dieting in any form is pretty safe and harmless. However, what we’ve now come to know through research, and clinical experience, is that dieting can lead to all sorts of complex mental and physical issues. Common issues include things like binge eating, feeling addicted to certain foods, anxiety, stress and shame around food, eating disorders and disordered eating, weight yo-yoing, or weight increasing with each and every diet attempt. 

For this reason, I take a Non-Diet approach and weight inclusive approach to nutrition (Intuitive Eating) which is an evidenced based practice that supports pursuit of health without focusing on weight or body size. This approach supports health promoting lifestyle which have been proven to improve health irregardless of changes in body weight. 

If you’re wanting to get started on this journey, sign up to my FREE 7-steps to find food peace and food freedom below! 

References:

1) https://www.ncbi.nlm.nih.gov/pubmed/27338458

2) https://www.ncbi.nlm.nih.gov/pubmed/29419624

The Game Changers is a Netflix documentary that follows the winner of The Ultimate Fighter, James Wilks. He was on a quest to find out how nutrition could improve recovery and performance, after suffering a major injury. The movie features several professional athletes, all touting a vegan or “plant-based” diet. 

The main message of the film: Plant-based diets are the key to athletic achievement and health. 

This is quite a loaded message, so we will break down some of the documentary’s main points here.

One of the first big impact statements of the Game Changers documentary is when Wilkes describes becoming injured after a sparring match and subsequently spends 1,000 hours studying peered reviewed articles on how nutrition can improve recovery. It’s a statement was used to create credibility. However, all I could think about is the process that it takes to become an expert in nutrition, or a registered dietitian.

While Wilkes read about nutrition for quite some time, it unfortunately cannot be compared to that of the education a qualified nutrition expert receives. 

Often times in our culture, people who live in fit bodies give nutrition advice that is accepted by the general public because it is assumed their leanness correlates to their nutritional expertise. This is one of the many ways in which our biases or internalised human preferences manifests in our everyday lives.

When seeking nutritional advice, registered dietitians and registered nutritionists are educated professionals in the field. While Wilkes surely meant well, this documentary could’ve been more a lot more factual had it included and collaborated with an expert in the complex field of nutrition. 

Let’s discuss some of the claims, faults, and truths of the Game Changers Movie.

Are eating plants good for us?

Of course! Nutrition experts have been saying this for years! But, to eat more plants, you don’t have to become a vegan or vegetarian. Plants and whole grains are high in dietary fibre which are associated with reduced cholesterol and reduced risk of heart disease.

While some may pursue a meatless diet as a means of protecting the earth, others may pursue this diet in order to justify disordered behaviours which can be problematic. Eating a vegan or vegetarian diet is not for everyone, but that doesn’t mean if you eat meat you cannot also eat plants!

Will transitioning to a plant-based diet give you more athletic endurance?

The film features an ultra-runner, a fight between Nate Diaz and Conor McGregor, and even football players. When these athletes made the switch to a plant-based diet, they found they had more endurance and energy. However, it’s likely that they were eating more carbohydrates than they were before as plant based protein sources tend to contain more carbohydrates.

Plant based sources of protein like beans, pulses and other starches do not contain all of the essential amino acids that our bodies need. In order to achieve a balanced diet. A variety of plant based protein sources are therefore, required. These plant based protein sources, tend to naturally contain more carbohydrates. Eating a low-carbohydrate vegan diet would be next to impossible. 

Finally, in our society, carbohydrates get a lot of heat, and often athletes eat too few carbohydrates out of a cultural fear that carbohydrates will slow them down. If these newly “plant-based” athletes ate more carbohydrates from the start, it’s quite possible they would’ve seen similar athletic benefits. 

What about the doctors featured in Game Changers who swear by vegan diets?

Several physicians featured in this film have financial stake in vegan diets. They profit in their own entrepreneurial adventures when the vegan diet succeeds. This is called a conflict of interest. For example, Dr. Ornish, Ornish Lifestyle Medicine, has authored several books and swears by a low-fat, high carbohydrate, vegetarian diet. Over the years he’s faced a lot of criticism for his claims that can come off as alarmist.

It should also be noted that dietitians exist as an allied health professional because doctors don’t receive the extensive training that registered dietitians do, in the field of nutrition. Medical school typically provide as little as one nutrition course. Physicians are certainly medical experts, but once again this film missed the opportunity to hear from a nutritional expert. 

Does eating meat really hurt how blood flows throughout the body?

Some football players from the Miami Dolphins were asked to eat either a bean or meat burrito. They tested the effect of a plant-based versus meat-based burrito on the blood composition of the players.

It appeared that the athletes had their blood drawn soon after eating (not in a fasted state), which was then taken in vials to a centrifuge. In a non-surprising outcome, their non-fasted blood draws showed greater fat content in the blood of the players who ate the higher fat, meat-based burritos. 

So what’s going on here?

When we eat, food travels from our mouth to the oesophagus, stomach, and then to the small intestine. As it travels, it is broken down by acid and enzymes. Once broken down and in the small intestines, the food is taken up by the blood stream for transport so that it may be used by the body. It is no shock that the group who ate more fat had fat in their blood-stream not long after digesting their burritos.

The film goes on to cite a study which tells us hamburgers hurt endothelial function (the lining of our blood vessels). Asker Jeukendrup, PhD, a world leading expert in sports nutrition critiqued this. He notes that the hamburger study which was hyped in the Game Changers film, had just eleven participants. In research, this number of people is not enough to make claims about all humans. 

The study which was not fully explained in the film, actually found that eating avocado, offset the effects of the hamburger. This was left out of the documentary. Also, the study was funded by the Avocado industry, which means there is a conflict of interest. 

(A conflict of interest means that financial or other personal considerations may compromise, or have the appearance of compromising a researcher’s professional judgment in conducting or reporting research).

Does eating plants help endothelial function?

There is some evidence to support plants high in nitrates, like beets, can dilate (make wider) our blood vessels. This means ingesting something beetroot juice can widen blood vessels and improves blood flow. This is something sports dietitians have known for some time and have recommended to athletes on a case-by-case basis.

Can I get enough protein on a vegan or vegetarian diet?

Of course! Our culture does place a huge emphasis on meat to get “big and strong” but we can definitely meet our protein needs without animal products. However, it can be a challenging task, so prior to making the switch, one should seek the advice of a qualified nutrition professional, like a registered dietitian or registered nutritionist.

Is a plant-based diet vegan?

The movie never defines what they mean by “plant-based”. Is it vegetarian? Is it vegan? Is it mostly plants with some meat? Who knows! The athletes seem to use the terminology interchangeably and this is a major flaw. 

Nutrition can be tricky and it’s not all black and white. It takes time, many lessons in statistics and expertise to be able to not only read but understand scientific literature. 

Take home message from the Game Changers: 

• Veganism and vegetarianism are acceptable way to eat.
• Veganism and vegetarianism is not for everyone.
• Eating more of the plants we like to eat, regardless of whether or not we eat meat, is good for our health.
• Documentaries like The Game Changers or What the Health are often sensationalised and use language that can be fear mongering.
• Finally, while studies have found there to be a reduced risk of certain health conditions when following a vegetarian or vegan diet, this is observational data. This means that large groups of people are followed/observed over time and associations are made. This sort of data cannot speculate that the vegan diet caused the person to be more healthy or have reduced risk of certain health conditions. We can only make associations. We also know from population data that those who follow vegan based diets,  then to be more “health conscious” in general.

My final thoughts trickle down to my public health roots. I would like to point out that having the resources to eat an entirely vegan diet requires privilege. It can be extremely costly to buy fresh produce, have access to that sort of food, and to have the proper utensils/appliances to be able to cook the foods you buy. Is being vegan good for the environment? Yes. Is it feasible for everyone? Absolutely not. Does being vegan make you more moral? Nope. The way you eat holds no moral value. Everyone’s circumstances are different and therefore a decision to pursue a meatless diet is a highly individual one.