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A Calorie Is Not Just A Calorie

We have all heard of calories, but do you know what a calorie is? Let the experts at Vision PT explain all things nutrition and calories.
Weight Loss Articles
Weight Loss Articles

By Kyle Sewell at Camberwell

Nesquik milkshake mix, white rice, chocolate blocks, fruit cups, Yoplait yoghurts, couscous, fruits, pasta, juice boxes, are all on the cards as Kyle indulges a high carbohydrate diet in the name of science.

I volunteered as a test subject, donating my body to science as part of a study being conducted by a leading university. This study was investigating the impact of sodium on the body in endurance athletes, specifically targeting three days prior to an event as well as the day of the event itself. Involved was four visits to the lab in which I would run (on the treadmill) at a controlled pace for an extended period of time to mimic endurance race conditions, in a heated environment to promote perspiration (sweating). For these visits, as a control I followed a set meal plan, with macronutrients, overall calories predetermined, and food provided. 

The food provided was specifically designed to provide a standardised amount of energy (overall calories) according to sports nutrition guidelines, high in carbohydrates and moderate to low in protein and fat (in comparison to my standard meal plan); basically, intended to give me fast acting, easily accessible energy tailored to a performance based outcome. At the time, based on my goal, body type, activity levels and fat free mass, my standard diet and daily macronutrient recommendations were 250g of carbohydrates, 190g of protein and 110g of fat giving me a total of 2750 calories. The nutritional breakdown of the meal plan provided on days during the study was (roughly) 450g, 100g, 90g of carbohydrates, proteins and fats respectively giving me at least 3010 total calories; not only were macronutrient ratios different but overall calories higher than in comparison to my normal diet.

It is important to remember that this meal plan with specifically designed to provide a standardised amount of energy according to sports nutrition guidelines and reflected a specific, performance-based goal. The meals were not undue or out of the ordinary and overall normal food intake and quality for the general population. Muesli or Corn Flakes and a banana was standard breakfast fare.  From there lunch options featured Vegetarian Paella, pasta with Tomato based, or chicken, garlic and ginger stir fry with white rice. Chicken tagine with couscous, pasta and bolognaise sauce, and mushroom Risotto were on offer for dinner. Snacks included yoghurt (the fruit flavoured kind), fruit cups, fruit juice, apple and handful of almonds rounded out the rest of the meals, with block chocolate as an afternoon indulgence/pick me up.

I approached this experiment and meal plan with an open mind and excitement and saw the food selection as a novelty as food selection was greatly different to my standard food intake with several of the items on the menu harkened back to my childhood. Soon after breakfast on the first day, the novelty of new and exciting foods wore off, I quickly realised that this experiment was going to be a challenge; hunger hit me with a vengeance. On the first day, by 2:00pm I'd eaten all meals and food provided bar dinner, which I'd deliberately saved, and I was ravenous. After each meal, there was the initial energy surge form the insulin and blood sugar spike, but then my energy levels plummeted, and napping was high on my list of priorities and I was given new insight into 3 0'clock-it is.

What I learned.

A calorie is not a calorie; although I was eating overall more calories, I was hungry and my energy suffered. I could have easily eaten double the amount of the same food and still not feel satiated.

Food quality and glycaemic load matter; a lot.  The food provided was mainly fast acting carbohydrates falling high in the glycaemic index with low GI and fibre rich carbohydrates lacking and the protein and fat content of food offerings were lower than what I was used to on my standard meal plan.

Fibre slows the release and energy breakdown whereas protein plays a major role in hunger regulation and satiation whilst fat has a longer and slower breakdown and energy release helping to regulate blood sugar and hunger hormones.

It is plain to see why 63% of the global general population is either overweight or obese and Type 2 diabetes and other lifestyle diseases are on the rise worldwide.  These foods were by no means "bad" or outside of the normal. On the contrary, the meals were very normal and a standard day of eating looked much like that of a large majority of the general population, but again, lacking adequate slow release and hunger satisfying nutrients, I could have eaten double the given food and still not be satiated.

This insight gave me new insight into my body. As I was used to a certain diet, I felt the impact of the change in food and new diet much more than if this new food selection was my norm. Furthering on, constant and sustained eating this way would lead to negative effects upon my body composition, weight & overall health.

A lesson in willpower; all in the name of science.

At the time, I was training for a Marathon, using these visits as part of my training plan averaging at least 2 hours for each of these visits as well as my regular training. I also have an efficient metabolism, relatively high percentage of lean muscle mass and low bodyfat percentage. These factors allowed my body to burn through the ample supply of energy at a rapid pace with no negative effects on body composition.

On the flip side, if I were to be living a sedentary lifestyle with minimal activity and a different body composition, the results would have been much different. In saying that, it was an exercise in willpower and finding ways of occupying myself and managing my hunger pains which saw me through as opposed to breaking and seeking more food to find solace for my hunger.  The accountability of having others relying on me being involved in this study and something greater than myself was a major driving force in continuing on.

Think of your goals.

Less is more; by choosing a balanced diet with whole foods, fibre rich, complex carbohydrates and adequate protein and fat it allows for less overall calories but more overall food and helps regulate blood sugar, energy levels, hunger and overall appetite and has a positive effect upon body composition and weight loss. The foods selected were directly linked to my energy expenditure and output and aimed at a single purpose to match my activity level, providing a standardised amount of energy according to sports nutrition guidelines and reflected a specific, performance-based goal.

And what about the salt?

The meal plans provided gave me a controlled and standardised amount of sodium, from there, salt levels were manipulated through capsules. When combined with the diet, these capsules provided me overall with either a low salt diet (roughly half the recommended daily amount for a healthy adult) or high salt diet (near three times the amount). When I set out and undertook this little project, I did not think of the impact that the manipulated salt intake would have. My performance suffered. During one of these visits, I suffered muscle cramps, wavering energy levels and dizziness to a point where I was questioning my ability to continue and complete the visit. Given that the circumstances and parameters around these visits were exactly the same and controlled.

On the flip side, upon a returning visit, my performance was vastly and noticeably different. As opposed to questioning my abilities and the completion of the task, I felt strong; as though I could continue running for another 2 hours beyond the required time. On top of this, my blood pressure was checked routinely with my blood pressure with noticeable variations in readings over the course of the study Why? I cite the variabilities in my performance and blood pressure readings as a result of the variable controls put in place to manipulate my sodium levels. We need salt to survive; our bodies rely on sodium for muscle contractions, healthy neuromuscular pathways and regulating and balancing water levels throughout the body.  It is critical for a healthy nervous system and thereby is ultimately need for optimal health. As well as the positive effects upon the nervous system, body's electrical impulses and muscular contractions (after all, the heart is a muscle and runs on electrical currents), salt has been shown to have protective effects against heart disease.

Everything in moderation.

As much as it is essential to bodily function and there are positives to a moderate sodium intake, there are just as many negative effects when linked to a high sodium diet. Exceeding the recommended daily sodium intake contributes to an increased risk of cardiovascular disease and stroke. High sodium intake also impairs cognitive function and has an impact upon your kidney's ability to remove waste products, balance fluid levels and control the production of red blood cells in your body. This impact on balancing and managing fluid levels can cause the body to retain water and impact body weight.

A note on body weight.

During each of these visits, as part of the testing, my bodyweight was measured routinely through the course of each visit, pre and post run. I found that there was an average of 4% bodyweight change over the course of each two hour treadmill session; that is an average of 3kg of bodyweight lost over a two hour period. As the study had parameters in place to purposely induce sweating and was looking into variations in hydration levels, this weight loss was not an account of changes to bodyfat but was just through fluid loss. As water accounts for about 60 percent of a person's weight, this highlights the difference between weight on the scales and actual body composition change and why solely using scale weight as a metric for progress can be misleading.

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