What should I eat for energy

‘Food is fuel’. I hate the phrase, as I feel that food is so much more than that. It’s taste, it’s colour, it brings people together, it comforts and it celebrates. Food is one of the greatest pleasures in life and to reduce it to something which serves only to help us to burpees is paying it a disservice.

That said, food IS the thing which gives us energy, and in this article I’m going to tell you how to get the most energetic bang for your dietary buck.

Energy is something that we ‘feel’ throughout an entire day, week and year, and what you eat on a daily basis will affect that strongly. In fact the effects of your nutrition come second only to sleep when it comes to feeling great day-to-day. If you are consuming a diet which is not set up to provide energy for you and your unique physiology you will not only suffer poor performances in boot camp, you will have energy lulls during the day, you might have ‘up’ and ‘down’ days, and you can even have fluctuating energy levels on a month-to-month basis. Getting this all level, optimised and running as efficiently as possible will improve your overall health and allow you to train harder and for longer, but it will also make you feel awesome outside of the gym too.

So HOW does food give us energy?

Energy is measured in joules, and we need a certain amount of it per day in order to live, thrive and perform tasks from walking up the stairs to completing that final burpee. When talking about food, energy is spoken about in terms of Kilocalories, shortened to Kcal. We often use the word calories in conversation, but the actual figure we mean is Kcal which is 1000 times larger. One kilocalorie is around 4.184 Kilojoules, or 4184 joules – the amount of energy needed to heat one litre of water by one degree centigrade at a pressure of one atmosphere. It’s a pretty specific unit (1).

As you probably know, foods contain various nutrients in varying amounts, from tiny trace amounts of micronutrients to comparatively large gram amounts of macronutrients, namely protein, carbohydrate and fat. These are referred to as macronutrients because we need a lot of them on a daily basis to function properly, and they are the things which our body can break down to use for energy.

The energy in a given food is calculated by finding the macronutrient content of that food and doing some basic multiplication. I won’t explain how we know this in this article, but we know that carbs contain around 4 calories per gram as does protein, and fats contain 9. 

This food is passed through our body into the stomach and gut where it is digested, and where the energy is ‘extracted’. The digestive process breaks the foods down into their constituent parts. Fat becomes fatty acids, carbs become glucose and protein becomes amino acids (which can also be then turned into glucose if you eat too much protein). Both glucose and fatty acids can be used for energy by your body to do the things you want to do day-to-day.

Whilst both carbs and fat eventually become an energy source, they both give us energy in a slightly different way. Fat requires the presence of oxygen to be used as energy which means that for general daily activity, moderate or steady state exercise like jogging or swimming, and working a regular job, fat can be an ideal fuel. Carbs, on the other hand, are used more efficiently by the body and can therefore be used for energy without oxygen. This makes them PERFECT energy sources for highly intense training, but it also means that some people will be able to fuel their daily activity with carbohydrates and feel fantastic: alert, satiated, happy and focused.

What this means is that both fat and carbohydrates can be used for energy, and as I explain in the article, Nutrition Part 2, when it comes to fat loss or muscle gain what ultimately matters is calories and protein intake. What this means is that, provided you abide by a few rules, you actually have a lot of scope to do a little self-experimentation when it comes to finding what works for YOU in terms of feeling awesome.

The Rules

As noted in this article about nutrition for beginners there are a few baseline nutritional habits which are recommended under all circumstances to make sure you are healthy and you are giving your body its best shot at optimising body composition. Once these habits are in place you can then build upon them when designing your own personal approach. These habits are:

- Eat 7-11 portions of vegetables or fruit every day. These will provide you with all of the micronutrients needed to perform the metabolic actions required to get energy from food. Eating a good amount of various plants allows you to digest food much more efficiently and allows you to break down and use the energy therein to your full potential.

- Eat protein with every sitting, and aim for around 2 grams per kilogram of lean body mass. Protein is necessary for muscle growth and repair as a result of the hard training that you do, and it is best to split your protein feedings out over 4-5 meals than to eat it all at once.

- Drink water regularly. Water is needed for digestion and absorption of nutrients, as well as cell function and a TON of other things. Fill a bottle and keep drinking it.

What to eat for energy | British Military Fitness

- Eat to a rough schedule. Not only does this reduce snacking and make it far easier to keep calories in check, not leaving too long between meals is a great way to prevent your blood sugar getting too low. After a meal, your blood sugar is raised a certain amount (kept in a tight range by insulin and other hormones which stop it getting to dangerous levels) which provides your brain and other organs a ready stream of useable glucose. If blood sugar drops because you are waiting too long in between meals, you will feel tired and sluggish, but also incredibly hungry. Low blood sugar makes you crave food, which is a bad idea for those looking to keep their intake under control.

- Roughly count calories. Calories are energy units and we need to be sure we get enough, but not too much. The simplest way is to quantify it by putting a number on it. Follow this link to find out how to find YOUR number.

Once you follow these rules and have been doing so consistently for a few weeks - long enough to make it second nature - you need to then figure out your individual variances. The simplest way to do this is on a meal-by-meal basis starting from a baseline.

We have established a rough protein goal, calorie goal and meal frequency, as well as a vegetable intake. The only thing left for the meal is to properly determine carb and fat content, as well as sources of these nutrients.

As a rule, those of us who exercise regularly (especially you who take part in boot camps or other intense training activities like weight training) should be consuming at least some of the rest of their calorie allowance via carbohydrates, whether the goal is weight gain, loss or maintenance. The reason for this is that, as I mentioned above, any activity which is anaerobic in nature (done without oxygen) such as a sprint, set of burpees, set of squats or anything else that couldn’t be considered ‘endurance work’, is fuelled without exception by carbohydrates. Going to boot camp? You need at least some carbs (2).

As another rule, it’s not a good idea to reduce fat too far. We need fat for the absorption of vitamins A, D, E and K, to build and maintain every cell in our body and to regulate hormones etc properly. Therefore creating a deficiency in dietary fat can cause a whole host of problems.

With these two things in mind, your baseline diet will contain both fat and carb sources in every meal, along with protein and vegetables, and will roughly meet your calorie needs. An example meal would be steak with buttered potatoes and steamed greens, or a Spanish omelette. Tasty, simple, balanced.

The variables

From here, we can start to play around with things to find what is optimal for YOU. Individual variances in how we feel after food are pretty vast due to genetic sensitivity to carbs, ability to use fats readily as fuel, and how you personally respond to different food sources. The first thing I like people to try is to replace non vegetable carbohydrate sources in their meals which don’t come around the training window with extra fats, for the same calorie load. Try this and see how you feel in comparison to before. Are you more hungry? More tired? Or do you feel better?

After this, replace these fats with carbs to make a relatively (BUT NOT COMPLETELY – FATS ARE STILL IMPORTANT) low fat meal with a high carb count. Get a leaner steak and have two unbuttered potatoes, swap salmon for cod and have more rice, etc. Ask yourself the same questions and see what you come up with.

Over time you will start to see that one pattern of eating suits you better than others, and this is the way you should play it. Most people deal well with a lower carb breakfast followed by moderate carb and fat intake throughout the rest of the day. Some people, though, seem to feel like they have much more steady energy levels through the day if they keep carbs on the lower side for almost all meals, making meals with meat and vegetables with some form of added fat like cheese or olive oil the bulk of their intake. That’s fine if you are one of these people, but I would STILL recommend you get some form of carbs in your evening meal. At this time you won’t mind if the carb load makes you tired as you’re going to bed anyway, but these carbs will provide you with the fuel you need to nail your boot camp sessions.

So, you have your baseline diet and you’ve worked out your preferred split and layout of carbs and fats. The only thing that’s left to find out is how it affects you to use different food sources for energy. Throughout this article I’ve mentioned a few times that you should be comprising your diet of almost entirely whole foods, and this is true, but the magnitude of your specific ‘almost’ is again going to come down to the individual. What I mean is, some people can eat a few more ‘suboptimal’ foods than others.

The thing you can consider switching up and going a little ‘suboptimal’ is going to be your carbohydrate choices. Why not protein or fat?

Protein sources are FAIRLY limited. You want to aim for animal based protein sources pretty much all of the time, as these are the ones which will break down into a complete range of amino acids in the correct ratios to be used by the body. For vegetarians, please check out this article about nutrition advice for vegans and vegetarians for more specific details.

Likewise, for fats you want to be aiming for a good range of sources all of the time. Briefly, fats can be categorised as polyunsaturated, monounsaturated, saturated and trans fats. The first three are found in animal products, nuts, seeds, olive and coconut oils and other wholefood sources. The last one are found in processed food products in the form of hydrogenated fats.

So, really, your protein and fat sources are going to be pretty similar no matter what you do. It’s not going to make much of a difference to your energy levels whether you have peanut butter or avocado, or lamb vs pork. However, I find that most people have the steadiest energy levels when their carb sources revolve around those which are generally considered ‘healthy’, namely rice, potatoes, oats, wholegrain pastas and breads if tolerated well, and fruit. This should be the bulk of your carb sources if your overall goal has anything to do with being healthy

But that’s not to say that you CAN’T have other things. For more on eating flexibly, which is a fantastic tool to increase the success and enjoyability of your diet, head over to the article about food and drinks to avoid.

Final Thoughts

So there you have it. Summed up, your diet should start to look like this:

  • The right amount of calories, roughly tracked, eaten over 4 meals or so at regular intervals (no need to be too precise about counting kcals, here)
  • Protein at every sitting, totalling about 2g per kilo of bodyweight
  • Vegetables or fruit at every sitting totalling 7-11 portions
  • Water as your main source of hydration
  • Carbs in the evening meal no matter what

After that, you need to experiment to find your personal preferences with regards to:

  • Carbohydrate and fat intake in other meals
  • Specific carbohydrate choices
  • Take your time and really listen to your body as it tells you exactly what it needs. Your energy levels and the way to optimise them are entirely individual.



  • (1) http://www.medicalnewstoday.com/articles/263028.php
  • (2) Phinney et al. (1983) ‘’ The human metabolic response to chronic ketosis without caloric restriction: preservation of submaximal exercise capability with reduced carbohydrate oxidation.’’. Metabolism, clinical and experimental.
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