Calories in V’s Calories Out – Not So Simple…………

Weight loss is hard, yes? There wouldn’t be too many people out there that would disagree with me. Nearly all of us watch our weight, if not all of the time, at least at somestage in our life – and we should. It is part of living an healthy active life, and being mindful of our consumption (as overconsumption is so easy to do) and to be aware of what we eat, when we eat, and why we are eating.

I know I have mentioned to you all that watching your weight is a simple equation on calories in V’s Calories out, but I have also mentioned to you that everyone is different and everyone metabolises foods differently, due to your lean muscle mass composition, genetics, type of exercise you do, your hormones, stress levels just to name a few. Also, you all have different fitness levels that affect your ability to burn calories. You also know that I am a big believer of high intensity interval training, and that this is more beneficial than say, walking, for fat loss and increased fitness.

So, that said, here is an article written by the very clever Andy DuBois that may better explain why some of you are finding it easier than others to lose the weight. It also explains why I am so focused on you eating not a low calorie diet, but a HEALTHY diet. And why I also bang on about the obvious importance of exercising regularly, and at the right intensity for your desired outcome.

I have highlighted a few good points that I want to focus on and hopefully this will explain more about the differences in food (and why I hate white stuff!). It also mentions that there are inaccuracies with tools of measurement such as Heart Monitors and calories counters etc. While this is true, without the use of these tools many of us would have absolutely no idea of the calories in foods and how many calories you burn during exercise, so these tools are still invaluable even if they cannot be measured exactly. They allow you to take an element of control over your diet, but more importantly, your exercise and eating behaviour.

Happy Reading!



Fat loss is easy, all you have to do is eat fewer calories than you burn, or so many people would have you believe. If you aren’t losing weight then you are either eating too much or not exercising enough. Unfortunately the human body is a little bit more complicated than that and the calories in vs calories out model of fat loss has some serious flaws.   It’s all about balance yeah?


1. Food isn’t just calories.

One assumption calories in v’s calories out makes is that the all the food we eat is converted into calories. This assumes that whether you consume fat , protein or carbohydrate (macro-nutrients) it is all going to be used for energy and no other purpose. This is an incorrect assumption. Protein is used for muscle repair. It is also found in our hair , nails , skin and brain and it can be converted into a number of hormones essential for the body to function. Fat is used for insulation , it is used in cell membranes , it makes up part of the fatty sheath that surrounds nerve fibres, it helps with the absorption of some vitamins and is a key ingredient in hormones and other chemical substances that are vital for the body to function. Carbohydrates are almost solely used for energy. So depending on what you eat a certain amount of the macronutrients will be used for maintaining the cells in our body. A meal high in protein and fat will have a percentage of its potential calories used as building blocks for the body whereas a meal high in carbohydrates will be used solely for energy.


2. The numbers don’t add up.

According to the calories in v’s out argument if I ate 100 fewer calories per day for a whole year I would lose 36500 calories or approx 4 kilos of fat. That sounds great you may think. What if I then kept this up for 10 years. I would then have lost a total of 40 kilos of fat. I currently weigh 67 kilos so I would then weigh 37 kilos! Now 100 calories is approx 1 slice of bread . So I wouldn’t exactly be starving myself.   The good stuff There have been a number of studies that have shown that people eating the same amount of excess calories put on vastly different amounts of weight. If the calories in v’s calories out theory is correct then the amount of weight gain should be very predictable, instead it ranges enormously. Studies have also shown that it is possible to gain weight when eating fewer calories than your body supposedly needs to maintain weight.


3. It takes energy to store energy.

Energy is required to convert food into a form of energy that can be stored by the body. The amount of energy required depends on whether it is carbohydrate, protein and fat and which scientific paper you read! The macro nutrient composition of your meal will affect how many calories are burned in converting food into a storable energy source.


4. Different macro nutrients affect our bodies differently.

Hormones such as insulin and glucagon affect our fat storage or fat usage systems. Other hormones like leptin and ghrelin affect our feeling of hunger and satiety and all of these hormones are influenced by what we eat. The primary influence is not the amount of calories that we eat but the type of food we eat. If the calories in vs calories model out is correct then it shouldn’t matter if we obtain all of our calories from pure sugar or from lentils. If we eat fewer calories, then we should lose fat. But sugar has a vastly different hormonal effect on the body than lentils.


5. Inaccuracies measuring calories.

If the low-calorie theory is correct, then it is important to figure out how many calories we need to eat and how many we are burning per day. After all, 100 calories extra and you will put on 4 kilograms in a year! It is almost impossible to measure either the amount of calories you eat or the amount of calories you burn to anywhere near that degree of accuracy. Any watch or machine that tells you how many calories you burn is making some pretty big assumptions. The amount of fat and muscle you have will affect your calorie usage, your genetics will also affect it, as will the amount of sleep you had, the temperature, the time of day, your stress levels and numerous other factors. There are numerous calorie counters that will tell you how many calories are in a certain foods but the level of accuracy of these is very questionable. How many calories in an apple for example , a quick search on the net shows anything from 70-120 for the same size and type of apple. If you are measuring everything you eat, and using a state of the art watch to measure your calories burned you are still only going to have an estimate that is maybe several hundred calories out. Clearly this isn’t a good way to go about losing fat.


6. All exercise is not the same

The more calories we burn during exercise the better. Right? Well what about exercise that doesn’t burn as many calories during exercise but raises your metabolism after your workout? What about the hormonal response to exercise? Different exercise affects our hormones in different ways and our hormones affect fat storage , fat usage , muscle growth and numerous other bodily functions. High intensity cardio or weight training involving full body exercises will elicit a greater hormonal response than going for a walk. But if calories out is all that matters then whether we walk for 60 minutes or do weight training for 20 minutes as long as we burn the same amount of calories it shouldn’t make a difference. In the real world, weight training or high intensity interval training will have a far greater fat loss benefit than walking (comparing workouts burning the same amount of calories)

Why do some people lose weight when they count calories? The primary reason some people are successful is that when people calorie count they choose healthier foods as they are often lower in calories. It isn’t the fewer calories that promotes the weight loss it’s the healthier food choices.

So if counting calories doesn’t work what should you do? Whilst there is a raging argument going on between low carb, high carb, Atkins, Paleo, Dukan, South Beach or any of hundreds of other diets, I prefer to keep it simple. Eat a diet high in vegetables, a moderate amount of fruit, legumes, protein and good sources of fat, low in grains and cut out the processed stuff (it’s not really food).

Written by Andy DuBois, Mile 27


Love it, love it, love it! I hope you got something out of this. So, next time you head for that burger, fries, extra couple of slices of white bread or sweet biscuit, think of the response your body is going to have after digesting it.