In order to look after our bodies, we need to make sure we are providing it with an adequate amount of energy. However, there must be a balance between how much we consume and how much we use, which is important to maintaining your health. In some cases, such as when we have a specific weight-related goal, we may want to be eating in a calorie deficit or surplus.
What are calories?
Calories are a way of measuring how much energy is in an item of food or drink. Our bodies require energy to function correctly in terms of regular bodily processes, and even more so if we live an active lifestyle and participate in regular exercise. The food and drink we consume provides us with the energy needed to experience everyday movement and functioning.
A calorie deficit and calorie surplus are two different styles of eating. The difference between the two is pretty simple, and relates heavily to energy expenditure.
Energy Expenditure Explained
There are 3 different types of energy expenditure:
Resting energy expenditure - this includes the energy your body expends while at “rest” but completing regular bodily functions such as breathing and blood circulation.
Diet-induced energy expenditure - this includes the energy your body expends due to digestion, metabolism, absorption and storage of nutrients.
Activity energy expenditure - this refers to the energy you expend when you engage in physical activity. This could range from extremely active sports to something as simple as performing household chores.
How many calories you need will depend on these three types of energy expenditure as well as a number of factors including your gender, weight, age, and body composition.
Providing your body with fewer calories than it requires to fulfil these three different methods of energy expenditure will put you into a calorie deficit, consuming more will put you into a surplus, and consuming the exact amount will result in maintenance.
So how do you know how many calories to consume in order to reach your goal?
Step 1: You need to calculate your RMR. This is your resting metabolic rate which calculates how much energy your body burns at rest.
Males will use this formula to calculate their RMR: 9.99 x weight + 6.25 x height - 4.92 x age - 5
Females will use this formula to calculate their RMR: 9.99 x weight + 6.25 x height - 4.92 x age - 161
Step 2: Introduce your activity level
- 1.2, or sedentary (little to no exercise)
- 1.375, or lightly active (light exercise 1–3 days per week)
- 1.55, or moderately active (moderate exercise 3–5 days per week)
- 1.725, or very active (hard exercise 6–7 days per week)
- 1.9, or extra active (very hard exercise, training, or a physical job)
Step 3: Calculate how much energy your body needs for maintenance
RMR x activity level
Step 4: Adjust according to your goal
If you are wanting to eat in a calorie deficit, you should aim to eat less than your maintenance calories. If you are wanting to eat in a calorie surplus, you should aim to eat more than your maintenance calories. How much you increase/decrease by will depend on a number of different factors, but as a general rule of thumb, adding or subtracting around 500 calories should be suitable. In order to get more accurate advice, see a qualified health professional.
A calorie deficit is often used in order to lose weight. When you provide your body with less calories than it needs, it turns to stored energy or fat, therefore resulting in weight loss. After calculating the amount of calories needed for your body to be put into a deficit, it will be helpful for you to calculate your daily calories using a tracker such as My Fitness Pal. Some tips for eating in a calorie deficit include:
Preparing your meals at home - makes it easier to track calories because you know exactly what's going into your meals
Cutting out processed food - highly processed foods are often sugary and high in calorie
Portion control - eating smaller portions may help you to decrease your daily calories
Opt for low calorie foods and snacks
Conversely, a calorie surplus is often used to gain weight through the storage of additional tissue. If your goal is to gain lean muscle, you will need this extra energy to build muscle and strength. It is important that although you are aiming to gain weight and up your calories, you keep your diet nutritious and high in protein whilst drinking lots of water. You should also start slow with a smaller surplus and maintain a suitable training regime if building muscle is your main goal. Here are a few tips you may want to implement in a calorie surplus:
Eat lots of lean proteins, high quality carbs and healthy fats
Although you are trying to increase your calorie count, try do this in a balanced way that focuses on whole, unprocessed foods rather than foods high in fat and sugar
Increase the amount of snacks you have during the day
Increase the portion size of your meals
True Protein’s All-In-One blend can be useful in both a calorie deficit and a calorie surplus. True All-In-One is the perfect product to assist your weight loss journey. With 25g of protein, 9g of fibre and less than 7g of healthy fats, it is a quick and healthy shake that can help reduce your caloric intake whilst keeping you full for longer. True All-In-One means you always have a nutritious and convenient option on-hand for busy days or when emotions or hormones might be tempting you towards unhealthy choices.
As well as aiding weight loss, All-In-One can also help you gain or maintain weight. True All-In-One can be used to help tip your energy balance into surplus while knowing that the calories you are consuming are good for you! Instead of using it to replace meals, try taking All-In-One as a snack (as well as your usual meals) to bump up your macronutrient consumption. If you want to maintain your weight, calorie consumption should equal calorie exertion, so ensure All-In-One is counted in your calorie intake.
Things to note when conducting a calorie deficit or surplus
It is important to note that you should not engage in extreme calorie surpluses or deficits as it risks a number of health complications resulting from malnutrition or obesity. A combination of diet and exercise should be used when engaging in a calorie deficit or surplus. You should ensure you are maintaining a healthy diet throughout, meaning you are eating highly nutritious foods, drinking lots of water and exercising regularly.
For personalised advice, please speak to your health professional, who will be able to assist you in determining the best plan for you.
Body Weight Planner | NIDDK. (n.d.). https://www.niddk.nih.gov/bwp
Hall, K. D., Heymsfield, S. B., Kemnitz, J. W., Klein, S., Schoeller, D. A., & Speakman, J. R. (2012). Energy balance and its components: implications for body weight regulation. The American Journal of Clinical Nutrition, 95(4), 989–994. https://doi.org/10.3945/ajcn.112.036350
Heymsfield, S. B., Peterson, C. M., Thomas, D. M., Hirezi, M., Zhang, B., Smith, S., Bray, G., & Redman, L. (2017). Establishing energy requirements for body weight maintenance: validation of an intake-balance method. BMC Research Notes, 10(1). https://doi.org/10.1186/s13104-017-2546-4