7 Short Lessons on Nutrition
Second Short Lesson
Thank you for showing interest in “7 Short Lessons on Nutrition”. I decided to write seven short articles because I believe that nutrition is at the base of our happiness -and among other things- it helps managing anxiety, depression, stress and low self-esteem.
In this article, I will be introducing the concepts that you need to know to stay in shape during the lockdown: Body Mass Index and Daily Caloric Intake.
The Body Mass Index (BMI)
The Body Mass Index is a measurement of “body size”. Its equation is based on the height and weight of an individual as follow:
BMI = (Weight in Kilograms) / (Height in Meters x Height in Meters)
The BMI was adopted in 1980 by the World Health Organisation (WHO) as the standard for recording obesity statistics around the world. The BMI scale is not relevant when applied to a single individual, but it is valuable to recognise weight changing trends within sedentary or overweight individuals across countries.
The BMI is a convenient rule of thumb to categorise individuals into one of four groups based on their estimated adiposity level (body fat):
- underweight, below 18 BMI
- healthy weight, 18 to 25 BMI
- overweight, 25 to 30 BMI
- obese, over 30 BMI
Do not worry too much about the group you rank in. The BMI has been around for almost 200 years (was used for the first time by Belgian mathematician Adolphe Quetelet in 1850), and scientists have agreed that this form of measurement can be unreliable when applied to a single individual. This discrepancy derives from the fact that the BMI scale cannot distinguish weight coming from the lean mass (muscle), the adipose material or the boney material. Furthermore, the BMI scale loses precision for individuals below 20 years old and over 60 years old, as well as individuals that are taller or shorter than average.
So why would the WHO choose such an inadequate measuring tool?
Firstly the BMI scale is easy to calculate. Secondly, it divides the population into categories that present similar health risks caused by unbalanced nutrition. For instance, underweight individuals tend to have nutritional deficiencies (lack of micronutrients) and eating disorders, while obese individuals are at risk of stroke, artery diseases and hypertension.
Anybody in the range of 18 to 30 BMI is in overall health and has good nutrition. Yet, remember that your body is optimally structured to maintain a BMI of 18 to 25.
Whether you consider the BMI to be an unreliable measurement or not, you must agree that the only aspect of nutrition in your control is your diet. In particular your Daily Caloric Intake.
Daily Caloric Intake
The Daily Caloric Intake is the amount of energy that your diet supplies to the body in one day. It is measured in kilocalories, and it is often compared with the Basal Metabolic Rate.
The Basal Metabolic Rate is the minimal amount of energy that the body consumes every day by performing vital activities (breathing, pumping blood, digesting, etc.). The remaining energy, consumed by your body while performing non-vital activities, such as walking, running, playing sports, etc. is called Active Energy.
The Basal Metabolic Rate combined with the Active Energy comprises the total Energy Expenditure of the body. If the Daily Caloric Intake exceeds the Energy Expenditure, the body is in an energy surplus; if the Daily Caloric Intake doesn’t exceed the Energy Expenditure, the body is in an energy deficit. In a balanced diet, total Energy Expenditure and Daily Caloric Intake are approximately the same (so, if want to eat more, just spend a bit more time training).
An optimal Daily Caloric Intake that fits all individuals doesn’t exist. The Daily Caloric Intake varies for each individual and should consider gender, age, height, weight and activity level of the individual. I am leaving a WeTransfer Link for you to download this Daily Caloric Intake Calculator*: https://we.tl/t-YZ2ipeO21R (There is also the meal schedule with my full diet).
*Available for 7 days only, but you can ask for it and I will email it to you.
Macro-Nutrients
If you did use my Daily Caloric Intake Calculator, you are probably expecting me to discuss the way calories are divided among macronutrients (Fats, Carbs and Proteins).
Let’s start from the fact that food and beverages nourish the body providing micro-nutrients and macro-nutrients. Micro-nutrients include vitamins and minerals, that do not have a chemical structure able to provide energy and therefore they have no caloric value; macro-nutrients include Fats, Carbohydrates and Proteins that provide energy to the body in different levels.
- 1gr of Fats contains 9kcal of energy
- 1gr of Carbs contains 4.1kcal
- 1gr of Proteins contains 4.1kcal
Notice that eating 50kcal of spinach or eating 50kcal of chocolate provides the same amount of energy. For instance, if you were to follow a calorie focused diet only, you could consume solely “junk” food and still stay under your fixed caloric intake, however, you would most likely be protein deficient and probably eat far too much fat.
Studies over the years have found that maintaining balanced macronutrients will help reach an optimal weight and overall health. Most diets suggest a 40/30/30 split (40% of your caloric Intake coming from Carbs, 30% from Proteins and 30% from Fats). Carbohydrates are the principal source of energy for the body; proteins help your body regenerating muscle fibres and are also very satiating; fats help with vital functions of the body, but we often eat larger quantities than needed. Lesson 4 will discuss the functions of macro-nutrients in more details.
You can have an idea of what a 40/30/30 diet looks like reading my meal schedule behind the Daily Caloric Intake calculator.
To help you reach your nutrition goals, I will share below the 3 rules that I use to keep my nutrition on point all year long.
3 rules to become an #IIFYM Master (If It Fits Your Macros):
1. Pay attention to Calories first, then Macros — adopting a diet that measures macro-nutrients can be difficult if you are not used to tracking macros. However remember that diets are supposed to make you feel happy, not stressed about tracking every meal. I would suggest starting tracking macros only after you have got used to measuring calories. (You can use the smartphone apps for meal tracking from Lesson 1)
2. Don’t guess quantities but measure them — when eyeballing sizes, you will always underestimate the number of calories on the plate. To avoid this, use a kitchen scale to measure what you are eating.
3. Make healthy versions of your cheat meals — To follow a diet over the long term, you need to enjoy it. So, if your favourite meals don’t suit your new diet, then swap some ingredients or cook them differently so that you can reduce their calories. Usually, home cooking these meals should be enough. If you do this, you might even be able to eat your cheat meals more often!
I hope you enjoyed the Second Lesson on Nutrition and look forward to the next lesson. Leave a comment below. If you like my articles and are feeling generous, share them with your friends.
Disclaimer: This article was not written by a qualified nutritionist nor doctor. The writer’s knowledge comes from scientific literature and other online courses. If you have medical conditions refer to your general practitioner.
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