Energy Balance

The most important concept that you need to understand when it comes to managing your weight over time is that of energy balance.

Energy balance is the main principle behind weight loss, weight gain, and maintaining your weight.

So, what is energy balance? Here’s the technical version;

“Energy balance in the body is the balance between how much energy is consumed and how much is expended. Positive balance is when intake exceeds expenditure and is associated with increases in body energy stores (weight gain). During negative balance, as in periods of starvation, body energy stores are depleted (weight loss).” (1)

…and here’s me trying to simplify it;

The energy that comes in to the body does so through food and the value of this energy is measured as calories.

The energy we expend is done via the work the body does, whether it be exercise or simply just living – moving, breathing, heart beat, the work of the muscles and much more. This is also measured as calories, usually referred to as calories burned.

‘I burned x amount of calories on my run today’. You burn calories doing everything else too, just at different rates.

Energy balance dictates your weight over time and it is measured as calories in versus out.

If you constantly take in more calories than you need weight gain will occur. If calorie intake and expenditure is matched there is no weight gain or loss – you’ll stay at a particular weight. If you expend more calories than come in through food you will lose weight.

Managing your weight is far more complex than this from a behavioural point of view but this needs to be addressed before you confront those challenges.

The reason you put on weight with too many calories coming in is that energy cannot just disappear. This relates to the first law of thermodynamics which states that ‘energy can be converted in form, but it cannot be created or destroyed’.

To simplify that statement just think that if you don’t eat food then you do not provide energy to the body. It doesn’t just get created out of nowhere.

On the flip side if you take in too many calories that energy just does not magically disappear. If the energy doesn’t get used it has to get stored, and it gets stored as body fat.

When you don’t take in enough calories to match the amount you burn then the body draws from reserves, and the reserve is …you guessed it – fat stores. Weight loss occurs but it takes time.

It’s easier to put on weight because of all the high calorie food we have access to. It can be difficult to expend more calories than we take in because there is a mismatch with the food products we have created and the environment we live in daily.

Humans burn a certain amount of energy per day, it can vary depending on how active you are but there is a cap on what a regular Joe or Jane can be expected to expend. Food products have turned up in a short space of time with ever increasing calories.

This is problematic.

It does sound simple, ‘just manage calories and you’ll manage your weight’. Two words, human behaviour.

We like to eat nice things and this makes things far more complicated. I won’t get sidetracked on behaviour as this is about the body.

Energy balance should really make sense and I hope I have made the concept clear.

I did mention that if there is no surplus or deficit of calories your weight stays the same – your weight isn’t mean to go up or down. It’s important to know your weight will change day to day due to several factors (I won’t go in to in this piece) BUT the average over time will be the same.

The time scale of energy balance is a very important aspect to understand.

Generally when looking after calories we do so daily, we try to account for the calories taken on board in a given day, and we try to account for the calories we expend in a given day.

But managing your weight should be viewed as a long term process. It’s all about averages over longer time periods.

Change takes time and fat loss is definitely not just an on/off switch, which is contrary to what we are told (and sold) in the media and on social media.

So that’s energy balance in a nutshell, things are slightly more complex than this as there are a lot of processes happening in the human body day to day, minute to minute…but it is the single biggest physiological factor in weight management.

If you are informed then you can make informed decisions, or maybe you don’t want to make the necessary changes…but you know the answer to managing your weight regardless.

If anything is unclear let me know.

Energy Expenditure

If we dig a little further a picture will start to form more clearly on the ‘why’ behind weight loss. It’s important to understand why things happen, and when you do you’ll see that you have a large amount of control over what happens.

Energy in comes from food and the value of the energy is measured as calories and it’s fair to say we can control this (in theory – human behaviour says otherwise).

Let’s take a look at the energy out part, when you understand what goes on you’ll see we have control over this to an extent as well.

Daily energy expenditure (the calories you burn every single day) falls into these categories;

Resting Metabolic Rate (RMR)

This is the energy expended by the body to maintain basic physiological functions e.g. heart beat, breathing, muscle contractions etc. You burn energy just living.

Thermic Effect of Food (TEF)

When we consume food there is an energy cost attributed to digesting it, converting it, and storing it. Don’t get too bogged down on thinking about this.

Exercise Energy Expenditure (EEE)

The amount of energy you expend exercising is an addition to that of basic function. We do have control over whether we exercise or not, therefore there is an element of control here about increasing calorie expenditure in some way.

Non-Exercise Activity Thermogenesis (NEAT)

This is the energy expended outside of exercise and basic function. The best example is walking the dog or working in a manual labour job. You’re gone beyond basic function – but you’re not exercising.

NEAT is a big one, we have a great deal of control over this daily. Even if someone works a desk job they still have the choice to move around more outside work versus the decision to sit around watching TV.

The difference over time of calories burned between someone who is active through NEAT and someone who is not active can be substantial. To read more about it click here;

The Importance Of NEAT

The outcome here is that we can try to control our food intake and we can also try and control aspects of our energy expenditure, this in turn helps us try to manage our weight.

Energy balance is the most important physiological factor in weight loss, and we can take control of it.

Does Food Quality Matter?

One of the first questions I get after explaining this to someone is ‘surely the quality of the food you eat must matter?’.

It does and it doesn’t.

You can lose weight by putting yourself in a calorie deficit and eating mostly junk food. You lose weight, but it isn’t necessarily good for your long term well-being.

It’s not sustainable as your health will suffer eventually due to a lack of nutrients in your diet. However, this has been proven before using McDonalds, ice cream and twinkies.

It was done to prove energy balance is the main driver for weight loss, but in your case don’t ever do it.

On the flip side to this you can put on weight eating only food you would label as ‘good’. Fruit, vegetables, nuts, seeds, fish, lean meat…all the good stuff.

I’m sure you’ve seen or heard of someone who says you should ‘eat clean’. You probably also have seen or heard of someone who eats clean and can’t lose weight, they think they are doing everything right but their must be a problem with their metabolism or something is going against them.

If you take too many calories in versus your expenditure it does not matter that the energy has come from these ‘good’ or ‘clean’ sources, that’s what is going against them.

Gluten free, organic or anything labelled healthy don’t have any special properties that can change the rule of energy balance.

In many cases gluten free products are quite calorie dense, so they would not be a good choice for someone trying to lose weight. If you are diagnosed celiac then obviously gluten free is a must.

Organic labelled foods usually contain the same calories as their ‘non-organic’ counterparts but the organic product costs more.

I covered this topic previously when comparing the cost and calorie content of almonds, click here to read the article;

The Energy Value Of Almonds

No advantage there for energy balance either. Too much energy is too much energy – it gets stored as fat tissue.

My way of viewing it is that ‘calories matter for weight, but the source of the calories matter for health’.

You are trying to address the two and have them work to your benefit.

If you want to lose weight a calorie deficit is needed. To maintain weight eat at energy balance. To gain weight eat in an energy surplus. Whichever one you’re doing choose most of the calories from nutrient dense food.

Vegetables, fruits, dairy, fish, lean meat, whole grains – preferably specific choices that you actually like.

The big thing with sticking to the plan and it working is that is has to be sustainable, if I tell you to eat plain chicken breasts and broccoli every day at 6 p.m. I don’t think things will work out for too long (unless you love plain chicken breasts and broccoli).

Eat food you like – this can take a little bit of figuring out but it’s very important for long term success. Seek out recipes and meal ideas, ask friends, or even better ask people you know who are on the same path with nutrition.

So we know that our calories don’t have to be totally ‘good’, or we don’t have to ‘eat clean’ to lose weight. This means there is a small amount of room for some of the things labelled as ‘bad’.

You can fit things in if they are accounted for properly, and along with picking good foods you like this will help you stick to the plan long term.

The caveat here is that junk food is what is described as hyperpalatable.

Hyperpalatable foods contain some combination of fat, salt and sugar and usually taste pretty amazing. The calorie content is relatively high and they don’t fill you up or provide much nutrient value – they have been engineered for you to want more.

Make sure a little bit of something bad doesn’t very quickly turn into a lot of something bad.

This might sound cynical, but large food companies like money, they are more interested in that than your weight or health.

Eat to the your calorie goal, mostly nutrient dense food, have a small treat here and there but keep tabs on it and stay disciplined.

Good Food, Bad Food. Is There Such A Thing?

Now that we have covered energy and where food quality fits in it’s a good time to discuss my thoughts on labelling food ‘good’ or ‘bad’.

When we think of good food something like fruit or vegetables spring to mind – blueberries or broccoli perhaps. Fresh, nutrient dense, good for health.

When we think of bad food we associate it with junk food like McDonalds or milk chocolate. Poor nutrient value and associated with weight gain.

Here are two scenarios for you to consider;

  1. Someone is stuck in the middle of a desert and is close to death. They come across a Big Mac, some chocolate and Coca-Cola. This is supposed to be bad food, but if the person eats the food and it gives them enough energy to survive and walk to safety is it really so?
  2. The second scenario is someone who is perfectly healthy. However, they start eating large quantities of avocado, which is labelled as a ‘healthy fat’ and would be considered good. If the person keeps eating too much (too many calories in versus calories expended) and their weight keeps increasing and increasing toward unhealthy levels of body fat, is the avocado really good for them in the end?

Everything depends on context.

The exception here would be trans fats, they should be avoided at all times and if you have any underlying medical conditions or family history which means you should avoid certain food types.

If somebody labels a food as bad think about this part of the article. Everything is context driven and I also think it is very important for you to think for yourself.

A lot of times people will just repeat something they heard or read from an inaccurate source, so it would serve you well to always question things and look for the correct answer especially when it comes to nutrition.

If there is anything you hear and are unsure of please mail me and ask for clarification, if I don’t know the answer I will seek it out for you.

Does Meal Timing Matter?

No (kind of).

For energy balance what you do in a 24 hour period is what matters and then beyond that what you do over a period of months and years.

The longer answer is slightly more complex than this, but the short answer is no. You’ll see why that is the case once we look at the following…

You may have heard these before;

  • Breakfast is the most important meal of the day.
  • Eating lots of small meals stokes your metabolism.
  • Eating late at night, or even after 6 p.m. makes you put on fat.

These statements are false, and they are examples of what I said earlier – people repeat things they have heard even though they don’t really know whether or not they are true.

Eating breakfast does not make you lose fat if you eat too many calories over the course of 24 hours, and in turn over longer periods of time.

If you like eating breakfast, eat breakfast, but it cannot alter the rules of energy balance. You won’t lose weight just because someone said it’s important.

Who said it’s important? Probably the food companies selling breakfast products.

If someone eats breakfast and it makes them stick to their calorie goal, perhaps a deficit to lose weight, then eating breakfast is a great strategy, but it does not hold some magical fat loss power on it’s own.

This is a bit of a side note but sometimes I hear people say ‘I have no energy if I don’t have breakfast’. That’s grand, eat if you need to…but be really self aware about things, unless you have a medical condition you shouldn’t struggle for energy throughout the day.

This is a symptom of leading an unhealthy lifestyle. Get enough sleep, eat to your energy needs, do some exercise, stay active outside of that too and get some fresh air every day. People who go home after work and fall asleep on the couch…this should not happen as an adult. You need to take a serious look at your lifestyle as a whole.

Back to business…

Eating lots of small meals cannot alter the rules either. If someone eats 1 meal of 2,000 calories or 10 meals of 200 calories their energy total for the day is still the same. This is what influences your weight.

The ideal meal frequency usually differs from person to person and whatever makes an individual stick their plan is what is needed.

If you like eating lots of smaller meals go for it, if you like eating less, but larger meals, go for it. Consistency over time is EVERYTHING so you must find a way that suits you.

Think about this – some people are not satisfied by eating smaller portions of food spread throughout the day, they need larger meals with less frequency to feel satisfied and keep hunger at bay. Managing hunger is important when trying to lose weight.

Lastly, eating late at night does not change any of the mechanisms of fat storage or the law of energy balance. It may affect your sleep, you may feel bloated the next morning if digestion has stalled but you don’t put on more weight purely because you ate something at a particular time of day.

If you eat something at 5 to 9 at night or 5 past 9 the rules haven’t changed. Too many calories that day makes you put on weight.

If you eat enough calories to put you in a surplus at ANY time of the day this will cause weight gain.

Energy balance over a 24 hour period is the main principle.

A Closer Look At Food – Macronutrients

We had a brief look at expenditure but it’s time to look a little more closely at food. You now know that food provides the energy we need day to day to survive and to perform tasks beyond that.

The value of that energy in is measured in calories.

Food is broken into 3 main groups called macronutrients – they are protein, carbohydrate, and fat.

You may have heard of micronutrients, they are the vitamins and minerals contained within the food and if you want to learn more about them click here;

A Look At Micronutrients.

The 3 macronutrients do all have important roles in our diet beyond energy, but this piece is purely about energy. If you want to read about protein, carbohydrate and fat in further detail click here;

A Guide To Macronutrients

The vast majority of foods contain some kind of combination of protein/carbohydrate/fat, but most food types will be predominantly made up of one of them.

Typical sources of protein include chicken, turkey, steak, eggs, fish, greek yogurt.

Typical sources of carbohydrate include oats, bread, pasta, potato, rice.

Typical sources of fat include olive oil or any similar oil, nuts, seeds, avocado, dairy.

Here is the energy value of each of the macronutrients and I’m going to provide you with an example which will show you how it applies.

Protein – 4 calories per 1 gram

Carbohydrate – 4 calories per 1 gram

Fat – 9 calories per 1 gram

Alcohol – 7 calories per 1 gram*

*I’m going to include alcohol in this section as well as it has a calorie value and is something that affects weight management so it is important to mention, but just remember it is not classified as a macronutrient.

A pot of Flahavans quick oats contains 150 calories. Oats are typically associated as being a source of carbohydrate, but like I said earlier a lot of foods have some combination of all 3 macronutrients.

The breakdown of the 150 calories in the pot of oats is as follows;

25 grams of carbohydrate.

5.2 grams of protein.

2.6 grams of fat.

You can see it is mostly carbohydrate, and there are small amounts of protein and fat.

We know that carbohydrate is 4 calories per 1 gram, so multiply the 26 x 4 = 104 calories.

We know that protein is also 4 calories per 1 gram, so multiply the 5.2 x 4 = 20.8 calories.

We know that fat is 9 calories per 1 gram, so multiply the 2.6 x 9 = 23.4 calories.

If you add all the values together you get 148.2 calories.

This shows you how the energy value of food is broken down in this particular example, and it does also show that food labelling is not always 100% to the T accurate.

All food has an energy value, and it is made up of some combination of protein, carbohydrate and fat (in some cases just 1 or 2 of the macronutrients).

While we are on a food considered a source of carbohydrate it’s a great time to tackle the old chestnut of ‘carbs make you fat’.

No they don’t. Carbs are great for many reasons one of them being that high intensity exercise is fuelled by carbohydrate. If you’re training hard to any degree you’re going to need them.

Carbs don’t make you fat, carbs after 6 p.m. or 10 p.m. don’t make you fat, taking in too much energy does. You could eat in a calorie deficit – that is less calories than you expend to promote weight loss – with a lot of the food being from carb sources and you will lose weight.

Even if you eat late at night. Carbs late at night.

If you are still unsure of anything here, or if you have any questions please let me know.

Dietary Fat – It Is Energy Dense

If you look more closely at the energy value of the macronutrients you see that protein and carbohydrate contain 4 calories per 1 gram, but fat contains 9 per 1 gram.

That’s more than TWICE the energy value for fat.

A certain amount of dietary fat is needed each day to maintain your health, most fats contain health supporting properties, but just be aware that even if something is labelled as a ‘healthy fat’ too much energy still contributes to weight gain regardless of the source.

Dietary fat is energy dense, and energy matters for weight.

Finally, alcohol was mentioned as it contains 7 calories per 1 gram. It contributes to  energy intake (if you consume it) and is reasonably calorie dense.

Alcohol is energy dense, and energy matters for weight. If you’re out boozing every weekend and can’t figure out why you’re putting on weight then this is usually the elephant in the room.

Now that all the underlying principles have been covered, let’s move on to using different methods of said principles.

Different Types Of Diets All Come Back To Energy Balance

Low carb diets, low fat diets, the ketogenic diet, juice diets, the cabbage soup diet.

Whatever the diet, they ALL fall under the principle of creating an energy deficit to promote weight loss.

‘I’m going on a low carb diet’.

Restrict carbohydrates – you take a big chunk of calories out of the habitual diet.

‘I’m going on a low fat diet’.

Restrict fat, a food type, or if you’re only consuming juices daily, or if you’re only eating cabbage… it’s all removing calories from daily intake in some way.

There is no magic or secret to the particular diet, it all comes down to energy balance and usually the success comes from it actually suiting the client so they stick to it long term.

Timing is another example of where it’s calorie restriction at work and there is no magic to it.

An example of where by the time you eat can be controlled is intermittent fasting

Intermittent fasting is where a certain amount of time is spent fasting (no food intake) in a day, and then there is a window of time where food can be taken on.

Again, this can help reduce calorie intake over the course of the 24 hour period and may be beneficial for creating a calorie deficit.

Energy balance is the underlying principle of all diets, whether it be manipulation of macronutrients, specific food types, or timing.

Now it’s time to work out your calorie goal.

Calculate Your Targets


(1) ‘An Introduction To Human Nutrition’ from the Nutrition Society Textbook’