The current dogma that ‘all calories are created equal’ or ‘a calorie is a calorie’ is something that should be explored. There is so much information out there on nutrition, most of it conflicting and confusing to say the least. This idea that we can just assume all calories are equal in terms of releasing energy into the system with a breakdown of: fats giving us 9 calories per gram, proteins and carbohydrates releasing 4 calories per gram and alcohol containing 7 calories. If this was the case you could technically consume a diet of biscuits, cakes, chocolate and beer, so long as it fit you calorie requirements. It would also mean that calorie restricted diets would all work and you could then expect them to be a successful long-term option for weight control. Unfortunately as many of you may have tried it is not a simple as figuring out estimated energy expenditure and then merely reducing the amount we put in our mouths, if this was true the vast majority of us would be a healthy weight by now. There are a few reasons why calories aren’t all created equal; lets have a look at some of the reasons why.
These pictures both contain about 650 calories! Which one do you think is better for you?
One of the main reasons why a calorie isn’t just a calorie is that different sources of calories have immensely varying effects on our body such as impacting hunger, hormone regulation and the thermic effect of food. Even though we do need a certain amount of calories to function properly the sources are particularly important in controlling our weight and biochemical functioning.
A few key hormones control hunger and certain nutrients have different feedback mechanisms in place to regulate when we feel hungry or full. In terms of calories though this means that certain sources of calories will satisfy our hunger and others will not. Fructose, a sugar that is derived from sucrose, or as it is more commonly known table sugar, doesn’t have a feedback system in place so when we eat foods packed with added sugars we can seem to consume copious amounts before we are physically full. Foods also have different biochemical pathways in our body and sugar (sucrose, made from a molecule of fructose and glucose), the fructose component cannot really be utilised within the body so it is mostly converted to fatty acids and then stored as adipose tissue (fat) around the body. Proteins on the other hand have the highest satiety rating out of the macronutrients and therefore high protein diets can work as they keep you feeling full for longer.
The thermic effect of food is the amount of energy it takes to break down a certain nutrient. So although two different foods may have the same amount of calories, depending on the make up of the food will significantly impact on the net energy received after breakdown. Put into a formula it would look like;
Thermic effect of food=
Food consumed – energy to break down food = net energy consumed
Protein also has the highest energy expenditure requirements from the body to break it down and either use it for muscle repair or convert it to amino acids that may be required by the body for other essential chemical reactions. Carbohydrates come in second in terms of energy expenditure, followed by fats.
Bottom line; protein calories could be considered less fattening compared with carbohydrate and fat calories due to the thermic effect, or protein requiring more energy to be metabolised. Whole foods also demand more energy to be broken and digested over processed foods.
From a health perspective not all sources of calories contain vital nutrients therefore it is important to get a varied whole food diet with limited processed foods. As mentioned earlier that hormones can be effected by the foods we eat, additives can also mess around with our feedback mechanisms and tamper with the hunger control system, some additives have not been around long enough to know the full extent of there impact in our bodies and there are more and more emerging studies linking excessive amounts of additives to being carcinogenic.
Tips for shopping
Now that we are know that calories are not equal how do we then go about putting this knowledge to use?
Well, we all shop for our foods so let’s start there. When entering a food shop like Coles or Safeway, your best bet is to make a hard right or left depending on the store layout. On the outskirt of the shops you will find the majority of what you need for food, the fresh vegetable and fruit section, the meats, eggs, cheeses and yoghurts and the frozen fruits and vegetables, you can usually ignore the rest with the exception herbs and spices. When looking for other healthy options that might be in an aisle you will most likely have to look down near the floor or up high as they put all the best sellers at eye level to ensure you don’t miss the sugar laden addictive stuff. Always check the nutritional content if purchasing processed foods, check the sugar content, keep in mind that approximately 4g equals 1 teaspoon! You will be surprised how many teaspoons of sugar are added to processed foods, when comparing two products always compare the per 100g to get an accurate comparison. Also factor in the serving size, as some products might appear to have a low amount per serve when in actual fact you would consume double the recommended serving size. Watch out for ‘low fat’ varieties, in realities this can be translated to the ‘high sugar’ option.
Take home message; Calorie sources matter! They all have very different effects on our body; hunger, hormones, energy expenditure and are accompanied with vastly different micronutrients. Even though consuming enough calories is imperative to cover our basic needs; breathing, digesting, our heart beating, counting them or going on a calorie-restricted diet is not necessary for losing weight. In most cases it is more important on the sources of foods. Best advice for losing weight is to consume regular sources of protein to help regulate hunger and keep blood sugar levels stable throughout the day, eat plenty of fresh vegetables and fruits as well as healthy fats.
There’s a little bit of information for you to digest.
Mobile Personal Training Specialist
4 U Body Fitness