Is a calorie a calorie? In short, yes. A calorie is a unit of measurement. Just like a cm is a cm, and a tonne is a tonne, a calorie is a calorie.
One calorie is approximately the amount of energy it takes to heat one kilogram (or litre) of water by one degree Celsius. Calories measure energy.
Calories come from macronutrients – protein fats and carbs. 1g of protein or carbohydrate is equal to 4 calories, and 1 gram of fat is equal to 9 calories.
Yes a calorie is a calorie in terms of energy however getting 100 calories from carbohydrates is different to getting 100 calories from fat, or 100 calories from protein. The amount of energy (100 calories) provided by each macronutrient will be the same however the difference is that the body will use or process carbs and fats and proteins differently.
If you are simply counting calories, and you are in a calorie deficit then yes you will lose weight. Calories in vs calories out. Eat less than you are expending. However if you want to instead lose fat, and/or gain muscle then you must look further than simply counting calories, and instead count your macronutrients.
By counting macros you are counting calories by default (calculate by multiplying protein by 4, fat by 9 etc) however this way you are ensuring that you are getting the right amount of each macronutrient for your goals. If you are trying to build muscle and lose fat, yet you get all of your calories from fat then you’re gonna have a bad time.
To preserve and repair muscle you need protein so this is important if you are doing a lot of weight training. Proteins get broken down in to amino acids in the stomach, then travel through to the small intestine and are absorbed in to the bloodstream and distributed through the body to repair injuries and replace old or dying cells. Digestion of protein doesn’t begin until it’s in the stomach, whereas carbs start to digest in the mouth. If you are hungry then the first thing people usually reach for is a carb, this will “satisfy” you straight away because you start to digest it pretty much straight after eating. Protein takes time to digest, it makes you feel fuller for longer but if you are hungry it will not give you that instant satisfaction like a carb does. Anyway the point here was that protein is required for muscle retention and gain, so make sure you get enough of it especially if you are doing a lot of weight training.
Carbs are essential for energy, and also muscle growth. Carbs get converted to glucose and this is then used as energy (in a nutshell). Simple or complex carbs will affect insulin levels differently. They both have their place - simple carbs during a work out will get in to your system faster and give you instant energy, whereas complex carbs (from vegetables, wholegrains etc) take longer to digest and provide energy over a longer period of time. Hence the reason why low or high GI carbs can affect how full you feel after eating. In terms of body composition there have been a number of studies done on the affects of using low/high GI carbs and overall, body composition remained the same regardless of which type of carbs were consumed. It comes down to personal preference as to the type of carbs you include in your diet. The same amount of carbs from a sweet potato or a white potato will be processed in the same way, and give you the same end result, the only real differences between the two would be their micronutrient values.
Being that carbs are essential for energy, you need to make sure you are consuming enough for your daily activities and exercise. I have a high level of exercise with HIIT and weight training so I must fuel my body accordingly. I also need to make sure I am consuming enough carbs to assist with muscle growth.
And fats. Fats help with a number of processes in the body. They are essential for nerve and brain function and form a structural part of the brain tissue. Fats also help maintain normal heart function, and healthy skin cells. Essential fatty acids aren’t made in the body either so we need to incorporate fats in to our diet to cover this as these are required for growth development and cell functions. Fats also help transport some vitamins through the bloodstream (A, D, E and K) and also assist with forming hormones required to regulate a number of body processes. And the biggest thing? FAT IS FLAVOUR! A fat free diet makes for a boring tasteless diet and we all know the pitfalls of that! Ha!
So yes, a calorie is a calorie, and expending more calories than you are consuming will provide weight loss, HOWEVER if you have specific goals around wanting to lose fat (to lose fat rather than lose weight is a much better goal in my opinion), gain muscle etc then you must look further than simply counting overall calories. Counting macronutrients instead will be much more beneficial.