Exercise and weight loss: Do we know it all yet?

Watching The men who made us fat is a double-edged sword for me. I like to learn more about the food and fitness industries and I certainly learned a lot watching the show However, I do think the presenter Jacques Peretti has his own opinion and I can’t say it is completely accurate. I feel it is almost as biased as the industries he is trying to expose.

I feel the show is confusing the issue as does pretty much everything I read on nutrition or exercise. There is generally too much politics. They gloss over the fact that we used to be active all day instead of the little bit we are these days. More importantly, because we were active all the time, we were much fitter. So, when we were active, we burned more calories per minute than we do now. We had both quality and quantity of energy expenditure because the fitter someone is, the more calories they can burn per minute. Their body knows how to make this possible because exercise is about finding ways to burn more calories and get more done, so those who exercise more regularly get better at burning calories for longer.

During my degree, I learnt a lot about how the body uses energy, adapts to exercise and how we track the energy itself. I also learnt a lot about interpreting science and coming to my own conclusions. I read a lot of research at the time. Often off my own back because my personal goal was to understand how to treat diseases like obesity. My conclusion is that we don’t have perfect methods to track the body’s energy use of the body, and so we cannot draw perfect conclusions from any of our research. Frustrating, but that is a common argument in any area of research. I don’t think many people want to accept that.

Activity also has many more impacts on the human body than simple calorie burning and each can be essential to losing weight. To say it simply I feel a body needs to function properly in order to lose weight. That means it must know when to use certain types of energy and how to clean up the waste products they create. It also means that all the processes a working body requires to function properly must work correctly, including functions like sleep, so the body can repair all the daily damage that happens during the day.

By solely focusing on calories burned, people always miss the much wider and more important picture of the benefits of activity and a balanced lifestyle on the quality of our lives. This is a case of reductionism gone too far, as the implications of research are misinterpreted.

To counteract this, I try to distil everything into a common-sense approach that I can apply and believe in. The facts I am convinced of are that we used to eat more, yet we had very little obesity. During the rationing of the Second World War, people, on average, ate more than we do now.

The main and clear difference is the quality and quantity of activity in daily life. Back then, you had to move to live. Only the rich could be lazy, and funnily enough, only the rich had the health problems the West now suffers from.

This active lifestyle is, therefore, not an assumption. When I ask people how things used to be before the activities of life were so automated and easy, I find that people really did have to get food from the local shops every day because they didn’t have fridges and freezers. For example, my mum told me about keeping milk and butter under the sink!!! It’s what people used to do for centuries.

I use government data because it is open, generally methodically collected, and unbiased, as much as any data can be unbiased. It also reflects a large population, making the results more valuable. The trend is clear. We ate much more then than we do now. I only wish they had tracked activity as well. I couldn’t find this data for any country in the world, so I couldn’t make a comparison.

The difference is subtle. We didn’t do more intense exercise; it was gentler, but this adds up. I have not seen studies on the energy requirement of manual labour like washing, farming, mining and other active jobs compared to sitting at a desk typing. But I think it is safe to assume it was more taxing than our current work situation.

We often forget just how long we spend every day doing very little to tax our muscles and expend energy. Even adding small amounts of activity occasionally may not add up to much per minute, but per day it could be 50-100 calories or more which adds up to half a stone of fat per year. Funnily enough, that is about how fast many people add weight and why it is so hard to spot.

The truth is that you don’t have to eat much more to put on a lot of weight. All you need is a lot of time or just to stop moving. What is noticeable when you look for it is the lack of data on how much energy we burn on average per day.

There is no data on daily physical activity to match the data for what we eat. Recently, it has started to be recorded, but it just doesn’t go as far back as the data on nutrition. What the data shows is that we have consistently been burning fewer calories per day than we used to. Particularly over the course of a year.

We keep hearing that we are busier than ever, but this activity does not translate into movement as it used to. Of course, many people would still be bigger if they were active. That was true then as is now, but not so many.

Energy expenditure is complex

This represents a longtail of energy expenditure. We track the headline numbers of how much energy is burnt to move us a certain amount but not the less obvious aspects like the cost of cells regenerating in response to activity and energy lost as heat. We also don’t have perfectly accurate methods of tracking the stored energy consumed.

Add to that the other, deeper side of weight loss which is about consistency and a balanced life. Activity can have a powerful effect because it makes you want to eat and do the right things. It gets your cells to behave properly.

These wider and more complex effects of exercise are not understood or promoted very well, which means that only the obvious effects, like energy consumption, get attention.

Only when you consider the full impact of exercise or lack of it on your entire well-being do you realise the contribution it can make over a lifetime. That means understanding that you don’t want to do the right things when you’re tired. Activity can help improve your sleep but can take 4 months to have an impact.

Exercise also helps you:

• store and use energy properly,
• strengthen bones,
• use electrolytes better
• and improve mood,

What we do not know is how long these improvements will take for each person or the types of activities required. Often, the benefit is not the activity but the environment it puts you in. The social and emotional bonds you create and the experiences you enjoy have as much an impact as any direct physical benefits.

Activity also strengthens you so you can resist the impact of daily life. I am not the first to suggest that high cholesterol and added weight can be a consequence of lots of damage within the body. Being active makes your body better at recovering and thus repairing the damage. The body systems thus work well, and normal service is resumed. Energy is used properly, and you can and want to do what your body needs.

Proper activity and recovery are key to balance in life. This can never be appreciated when applying a narrow vision like TV programmes tend to.

So, ultimately, I see that these shows end up drawing fact from fiction because they do not consider the debate in the complex way it needs to be seen. Instead, they use statistics to promote the very confusion they aim to eradicate.

Wow, writing this article has certainly made me opinionated, but then, as a scientist and engineer that is how I have been trained. Truth is truth. If we don’t have the full data, we can not draw full conclusions. We must search for the full truth and not assume.

I am becoming increasingly confident in my opinions because I have researched extensively and then applied what I have found. It does not mean I am always bright, but I can see how each theory stands up to every test I can apply to it. Unfortunately, these programmes don’t present theories I can fully believe in.