What is more important for long-term weight loss? Nutrition or exercise?

Simon Long

Simon Long

Simon is a highly experienced personal trainer and behavioural psychology expert
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When it comes to weight loss, it’s all about that calorie deficit. Cals in vs cals out. If you’re eating the same number of cals as you burn in a day, then your weight doesn’t change. Eat more cals, and your weight goes up. Eat less, and your weight goes down.


So this gives you two options for lowering body fat levels. Either you can eat fewer calories (i.e. eat and drink less), or you can burn more (i.e. be more physically active). So which is the best option if you want to keep the weight off?


Surely diet is the way forward?

Let’s consider some numbers, and work out how much exercise it would take to burn off a bar of chocolate.


So an average bar of chocolate (let’s say a Dairy Milk bar from Cadburys) contains 240 calories.


The average female in the UK weighs 69kgs, and would burn 9.72 cals per minute if they ran at 5mph (8kph) on a treadmill. The average male in the UK clocks in at 84kg, and so would burn 11.84 cals per minute running at the same speed. 


Of course cardio is not the only way to burn calories (arguably it’s not the best either!). So how does resistance training stack up?


Well, data from the Harvard Medical School shows us that you burn about 0.72 calories per pound of body weight in an average half-hour weight lifting session. So the average UK male would burn 4.4 calories per minute, whilst the average female would burn 3.6.


So let’s assume our average male and female have each scoffed down a Cadburys Dairy Milk. And now they regret it and want to offset the calories. How long would each need to train?

Well, our female would need to be on the treadmill for 25 minutes, running at 5mph (8kph). Or alternatively, she could be hitting the weights for 1 hour and 7 minutes. Meanwhile, our male would be on the treadmill for 20.5 minutes, or they would be lifting weights for 54.5 minutes.


So looking at these numbers, it would seem clear that eating fewer calories is the way forward. As the amount of exercise you need to do is so high, that without a better diet there’s no way you could win. And this is true. For the weight loss part of your journey… 


What about keeping the weight off?

Research at the Harvard School for Public Health does agree that a diet only approach to weight loss is effective. However, the same study was also tasked with working out what was better for long-term weight loss. A diet only approach, or combining diet and exercise.


So they did what’s called a meta-analysis, which takes a number of studies that have relevant data, and then they see where the average lies. From their research, they found that a combination of diet and exercise leads to a greater long-term weight loss than dieting alone. To be clear on what we mean here, this is weight loss that is maintained for more than a year, or in some included studies two years. This importance of exercise for weight loss has been shown again and again. In fact the further you get into the weight loss maintenance segment of your journey, the more important exercise becomes.


So why is this? What is it about exercise that helps you to keep the weight off? The University of Lisbon ran a study to work this out, and it seems to come down to self-determination and self-regulation. So what are these?

Self-determination is a concept that refers to your capacity to make choices without being influenced by external factors. It is underlined by your sense of choice, your belief in your ability and how connected you feel to others. Exercise does improve these factors, but only when you’re doing the right exercise! This is why you should always focus on enjoyment and choice. By doing this you’ll improve your motivation to stick to the fitness training, which makes you feel more capable. Connection to others with exercise very much depends on how you see it but could be from training with others, or the increased social interaction you get as you feel better in yourself.


Self-regulation, on the other hand, is your ability to control your thoughts, attention and actions to stick with behaviours that get you to your goals, whilst avoiding those that hurt your progress. And studies such as the one conducted at the University of Lisbon show that there is a spillover from exercise self-determination to eating self-regulation!


This is why exercise is so important in the long run! It keeps your ability to control your actions in check, allowing you to keep your calorie intake down. And of course, the extra calories you burn and the improved health and fitness you gain is also a very nice side effect!


So what’s the takeaway here?

In conclusion, weight loss is never going to happen if you don’t get your diet in order. You have to reduce the number of calories you take in, which is achieved by eating less crap and reducing portion sizes. 


But! If you don’t include exercise, you may be able to get the weight off, but the chance of you keeping it off is reduced. 


So what’s a smart game plan here? Well, I would suggest the following approach, which is the way I go around it with my personal training clients (In Leicester and Online):


  • Start on a diet, so you can get the scales going down straight away (I have made an article before on how to approach a weight loss diet).


  • Next, begin trying out different types of exercise, so you can find which you really enjoy (Don’t limit yourself in terms of what counts as exercise. Jogging and the gym are only two of 100s of possibilities).


  • Keep at the exercise to build your confidence in your ability. Doing this whilst you are dropping the weight will also make the weight loss quicker (due to the extra calories burnt).


  • Once you’ve reached your goal weight, switch your focus to health and fitness-related goals! This will help you to stay focused, as often once people “cross the finish line” with weight loss, they begin to lose focus and slip into bad habits.


And there you go! Now you know the difference between nutrition and exercise for weight loss! Of course, you may have loads of follow up questions, so feel free to contact me. I’m available at si@bodydevelopmentcentre.co.uk, on my contact page, on 07890 587306 or you can message me on the Body Development Centre Facebook page


And of course, if you would like to work with me I offer personal training in Leicester as well as online fitness sessions. Both services will get you the same level of focus from myself, with my usual stupidly high level of focus on you as an individual, where we will look into your physical activity, nutrition and psychology (i.e. motivation, habits, enjoyment etc). 


I also have a mobile app available, Body Vision. This provides a training plan generator, as well as tools for building good habits and rebuilding bad ones. There is also a meal plan generator that is being filled with recipes as we speak! And best of all, it’s all absolutely free! So grab it for your Apple or Android device now!


And for those of you who are Leicester based and want some amazing hair to go with your new lifestyle, make sure you check out my wifes Instagram and Facebook for some amazing hair inspiration! Tip and trick videos and articles will also be coming soon!


And don’t forget to like my Body Development Centre Facebook and Youtube to keep up to date with all of my latest tips and tricks! I also upload videos to my Body Vision Facebook and Youtube, so you can follow me there too for even more Simon in your life! =]


But until next time, take care peps, and have a great day!


Best wishes,



Simon Long - Leicester Personal Trainer