6 fat loss myths debunked

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Much to my wife’s dismay. I’ve been deep into YouTube this week. I see her rolling her eyes as I’m seemingly glued to my phone. I try to proclaim its research but who am I kidding. However, I came across something that I thought was quite pertinent to what I stand for on this blog. Now bear with me on this because we’re going to go off topic just a moment before getting onto the title of the blog talking about fat loss myths.

I found a series of videos online about contreprenuers. This is a play on words from entrepreneur. Con meaning con artist. The premise is a group of individuals dedicating their time to exposing people who claim to be authorities in their industry and develop courses based on this experience.

These specific videos focus on property investing. A subject close to my heart as I dabble in this sector. Obviously, online courses and consultancy is my bag. So when I saw this the alarm bells started to ring.

As I watched more of the videos I started to realise these people are outright scam artists. Hardly any of them own a property between them but charge thousands of pounds for people for attending their courses. Suddenly I was able to relax. I am an accredited dietitian and thus registered and accountable for my advice. My courses are also a tad cheaper. Never will you see me charging thousands upon thousands of pounds. All my courses are below £200 and designed as a cheaper alternative to 1:1 consultancy. Phew.

A similar trend

This got me thinking though. There is a similar trend for health and fitness. A quick search online throws up hundreds of videos and articles looking at the best ways to lose fat and weight.

Some of this information is very good. Others outright terrible. Some people have a solid foundation of education behind them matched with years of experience. Others literally read a text book and call themselves an expert. I’m sorry but reading about a subject and being immersed in it day to day are 2 very different things. Some even only use themselves as case studies. We call this n=1. It’s a bad way to draw conclusions.

The big difference I suppose is with health and fitness, you can be your own testimonial. What you do might even work for some people. Ive no problem with that. My problem is the way the information is framed. If you have abs and look good, you must know what you’re talking about, right?

So today we’re looking at 6 fat loss myths I commonly see and I am trying to debunk them!

A new direction

All this got me thinking. I wanted to take a new direction with some of my blogs and videos focusing on opinion pieces. This will be based on my experiences of my sport and exercise science degree, working at a personal trainer and subsequently as a dietitian. I’ll try to throw in some research when time allows but my practice is inherently based on what years of research have already shown to be true.

Fat Loss Myth 1 – Just lift weights to burn fat

This one is very popular amongst the young gym community. Technically, they’re right. You don’t necessarily need cardio to lose fat and be healthy. This approach focuses primarily on lifting weights and avoiding cardiovascular work like the plague.

From experience, these kind of programmes are focused on getting the beach body. Using fitness models with bulging muscles or sculpted abs to market their approach or supplements. Yet, there are some serious flaws not discussed with this method that need to be addressed.

More often than not, the people endorsing this approach are young. Often in their 20’s. Still in their pomp. They’ve yet to develop the life commitments which limits the time you can spend sculpting a perfect body. Body builders, as we’ll call them, will frequently spend long periods in the gym. Taking long rest periods between sets in order to maximise strength and muscle gain. Sessions can and likely will last north of 2 hours.

Lifting weights

Fat loss myths. Resistance training is only good for weight loss

Now think about this. Lifting weights is a short duration activity. It last seconds at most split over various sets and repetitions. In order to generate an appropriate calorie expenditure to help you lose fat you need to either do it for a long time or really control the calories you are eating.

Being involved quite heavily in this industry in the past I have found actually it’s a combination of both. These people will spend hours in the gym. They will also control their dietary intake, sometimes to the gram. Tracking macros as it’s famously called in the industry. These diets can be very restrictive. I’ve personally seen example of these plans where the only foods allowed are chicken, fish, rice, green vegetables, eggs and porridge. I don’t even know where to begin on that so I’ll let you make up your own minds. That said, that diet will get you losing weight but it doesn’t mean it’s healthy.

So this approach will work, if you’re willing to dedicate you life to it. However, the many patients and clients I see who are not will to do this still struggle with their weight. They think just doing resistance training is enough to lose fat. It certainly helps, don’t get me wrong, but it is unlikely the only thing you need to do.

Fat Loss Myth 2 – increasing your basal metabolism through muscle building burns fat

I recently agreed to do a talk on exercise for weight loss for a CPD exercise for doctors and nurses at our hospital. To ensure I was being thorough I delved into the medical research to make sure what I believed to be true from my experience and previous research remained so.

One area I was looking at was increasing your basal metabolic rate to help with fat loss. If you are unfamiliar with basal metabolism, in a nutshell, it is your baseline calories you need to remain the same weight without moving or eating.

A common myth discussed is the metabolic advantages of building muscle to help lose weight. Again, there is some truth to this, to an extent and building muscle is definitely a good thing. I’m not questioning that. My problem with this is how it is overhyped as a major player in the overall outcome of fat loss.

Why does it supposedly work?

The premise is simple. Your basal metabolic rate is responsible for burning the most amount of calories compared to the thermic effect of food and physical activity. If you plot this on a graph it looks like this:

6 fat loss myths debunked

This is because basal metabolism is concerned with keeping everything your body does behind the scenes going. Things like your heart beating, lungs breathing, kidneys filtering etc all need energy to operate. This is then measured over 24 hours each day.

So the first thing to note is the time basal metabolism has to work. The thermic effect of food is small and for this discussion insignificant. So let’s look at exercise. Exercise is unlimited. Most people will not burn more than a few hundred calories over the course of the day through exercise. Others burn much more. It depends on how much you do. So exercise could be your biggest calorie burn if you wanted it to be but it’s likely unrealistic for most people.

However, the calories burned from exercise per hour will be much greater than your basal metabolic rate. Let’s say you need 2000kcal per day as a basal metabolic requirement. That’s 83kcal per hour. You can burn more than this with less than 10 minutes on a treadmill or cardio exercise. So pound for pound, exericise wins.

Taking it further

Another piece of advice is muscle is assumed to be 2-3x more metabolically active than fat. So pound for pound muscle burns more calories than fat. This is something I have found referenced in the literature and I’ve even mentioned this myself in previous blogs. However, I’ve yet to find any evidence that building muscle significantly increases your basal metabolism above carrying the same weight as fat. Therefore, we have a bit of a paradox.

What seems to be true is the heavier you are the more calories you need each day whether its from fat or muscle. So heavier people need more calories to stay heavier. Makes sense so far right?

This does pose a problem. It is estimated on average being obese increases your basal metabolic rate from about 50-850kcal per day. This depends on your level of obesity e.g. obese or super obese. If you build significant muscle mass that is the equivalent of obesity in terms of body weight, then need to eat more to maintain that muscle mass. In other words, in order to significantly increase your basal metabolism you then need to start really controlling your diet. So we are left with the same problem as myth number 1.

This is a healthier approach. No doubt about that. However, we’re discussing only fat loss here. You don’t need to go to the extremes of 6 meals a day and strictly controlling your diet in order to just lose fat.

Applying this to recreational exercisers

Assume most people are recreational exercisers at best. Yes they may build muscle but it’s unlikely going to be to the levels of top weight lifters, body builders or athletes. Even top athletes will unlikely achieve the upper additional calories to basal metabolism seen in super obesity without some additional help – if you get what I mean. If you don’t get what I mean, I mean illegal hormone use such as steroids, growth hormone, insulin etc.

So recreational exercisers are likely only going to see modest increases in their daily metabolic rate. For example, an increase of even 200kcal per day would be good but the work and dietary focus necessary to elicit this is likely much harder than actually expending this through additional exercise (a typical 70kg person running for 12 minutes on a treadmill at 12km/hr burns about 200kcal).

So once again, yes it can be done and the statement of burning more calories by building muscle is true but it is unlikely to be the difference. For me, this is an over complication of something that could be quite simple.

Fat Loss Myth 3 – cardiovascular exercise makes you fat

Fat loss myths. Cardio is bad for fat loss

Some so called experts will tell you cardiovascular exercise, more commonly known as ‘cardio’, will make you fat. This is just plain incorrect.

The reason they say this is because lots of cardio eats into your muscle mass. Hopefully, we’ve debunked how building extra muscle is a one way ticket to losing weight. Building muscle certainly helps, but don’t just rely on this unless you’re prepared to pay very close attention to your diet.

Yes, cardio will burn calories. Therefore, if your goal is build a substantial amount of muscle, lots of cardio isn’t the way to go. However, if you want to lose fat mass, some cardio will certainly help.

In fact, physique athletes who focus on achieving very low body fat percentages use cardio to help them. They split their training into 2 cycles usually. First, they build muscle by lifting lots of weights and eating A LOT. With this they tend to put on a fair amount of fat alongside their additional muscle mass. They then drop their calorie intake and begin using cardio exercise to help them drop body fat. Now most of my patients and clients are worlds away from this but it’s to highlight even the most dedicated people still appreciate cardio benefits.

This doesn’t mean you should only do cardio. Any good exercise programme involves cardio, resistance and mobility exercise.

Some of my patients do low intensity cardio and think they have burned more calories than they have. They therefore think they can eat more than they can and over compensate. This leads to weight gain but not nearly as much as they’d have if they didn’t exercise.

Fat Loss Myth 4 – walking is good for fat loss

Walking is one of the purest and easiest forms of exercise. When my patients can’t walk very far, their weight usually piles on. However, compared to other forms of exercise, walking is not a good form of exercise for fat loss.

The reason is it is very low intensity. With low intensity exercise you need to do it for a very long time in order to burn sufficient calories. A brisk walk will burn around 300kcal in one hour for the average 70kg person. When you think a normal 5km run on the treadmill for me burns 450kcal in 22 minutes, you can see the difference.

To help with fat loss, you need to do a lot of walking. Experts from an obesity conference I attended in 2019 suspected around 15,000 steps per day is needed for sustainable weight loss.

Excess Post Oxygen Consumption (EPOC)

One thing we should talk about is EPOC. When you exercise you place a demand on your body. This demand may be easily met by your body. Like with walking. Walking isn’t that hard for most people so your body can cope reasonable well. Therefore, your body is able to delver all the oxygen and energy to the working muscle in real time.

The more intense exercise becomes, the more demand is placed on the body. Resistance training and higher intensity cardio work place the body into an oxygen deficit. This means all the oxygen and energy can’t be delivered in real time. In other words, the body is still burning energy even after the activity is finished. EPOC makes up about 15% of the total calories burned during exercise. So it’s fairly significant. Returning to my 5km run example, I burn around 450kcal during the run but I am still in calorie debt well after I stop exercising.

The trade off is, higher intensity exercise is harder. It might not necessarily be appropriate for many of my patients. If you can increase the intensity though, it can pay dividends for fat loss.

Fat Loss Myth 5 – you need to look like a body builder to be healthy

The picture of health and fitness is of rippling abs and big muscles. Yet does this mean you’re fit or healthy?

Professional body builders are a good example. Some will be healthy but it’s no secret that to compete at the top level the athletes have to take additional substances. As mentioned, some use steroids, growth hormones, insulin, diuretics and the list goes on.

I’ve worked with tons of trainers who despite a good physique, couldn’t run for a bus. It doesn’t mean they were unhealthy. It means they were good at their specific type of fitness.

Just like endurance athletes who do not have rippling muscles, they can have tremendously well developed cardiovascular systems.

It’s a shame our idea of fitness is one of a well honed physique. Mo Farrah is an incredibly fit person but it’s unlikely you’d have him on your gym poster. This is because you associate the gym with muscles and Mo sadly has few of them.

Most of my patients want to be healthier and lose fat. Therefore, applying an approach of strict calorie counting and intense resistance training might not be the approach that best suits them. There is more than one way to skin a cat. So you can lose weight, lose fat and get healthier without following a body builders routine.

Fat loss Myth 6 – eating too little stops you losing fat

Another classic reason I hear as to why patients aren’t losing weight is they think they aren’t eating enough. You only need to spend a week working on the hospital wards to see what it looks like when you really don’t eat enough.

In fact, most dietitian’s job is to deal with under nutrition. Their job is to help people who can’t eat and trust me, when people are chronically under nourished they lose weight.

Imagine you found yourself on a dessert island with no food. Would you lose or gain weight?

So where does this come from?

The idea is if you don’t eat it slows your metabolism. We’ve already seen above the thermic effect of food on your metabolism. It’s small compared to your basal metabolism and exercise. Granted, if you lose weight, your body requires less calories to maintain the same weight. So you could argue it becomes easier to overeat. However, if weight loss is the goal in the first place, then why are you worried about this. If you lost weight, you’re working towards your goal.


There you have it. There are 6 myths to burning fat. These methods will work for some people. Often very dedicated, young people. For my average patient, these approaches may not be realistic. Instead, we need to help equip them with all the information available so they can make the most of their time during their weight loss efforts.

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