There are numerous weight loss suggestions available but we still struggle to find the one that actually works for each one of us.
Among the available options, the ones we go for are either diets or weight loss supplements and the reason behind this is the tiny but strong hope we have that these are the quickest ways to lose weight.
So coming to diets, most of us select a diet that has the best review and is convenient for us to follow.
We aren’t really aware whether it will suit us so we keep trying and testing.
Well, what if you could personalize your diet and tailor it to suit your needs?
And to do that, you need to understand the principle of calories.
What are Calories?
A calorie is a measuring unit just like kilograms and inches. What it measures is the energy provided by the food item.
Energy is crucial for our survival. Food consumed translates into energy we utilise.
Every nutrient is processed differently and therefore it provides different amounts of energy.
1 gram of protein or 1g of carbohydrate is equivalent to 4 calories while 1g of fat provides 9 calories.
Theoretically, 1 pound of body weight translates into 3,500 calories (Technically 3500 kilocalories but for convenience most literature quote it as 3,500 calories.).
So if an individual has gained 10 pounds he has actually consumed an excess of 35,000 (10 * 3,500) calories.
However this a just a theoretical viewpoint.
Why is Counting Calories So Essential While Losing Weight?
Having understood what a calorie is, you must have got a hint as to why calorie counting is so vital for weight management.
Every individual requires a specific amount of calories to maintain healthy weight and activity.
This is called energy balance and this is what it means in terms of weight:
- If you are maintaining your weight that means your consuming roughly the same number of calories that you are utilising.
- If you are gaining weight that means your intake is higher than what you need or utilise.
- If you are losing weight it means your intake is lower than your expenditure.
Since we are interested in the third category, we should look for what is called a calorie deficit. The basic formula is:
Calorie deficit= Energy utilized- Energy consumed
What happens when you create a calorie deficit, your body responds by burning fat in order to obtain energy from internal reserves and compensate for the deficit.
That leads to weight loss and loss of body fat.
But what happens is that we don’t count are calories right.
A study dated back to 1992 demonstrates that most individuals who complain that weight loss doesn’t work are actually under-reporting the number of calories consumed and overestimating the energy expenditure due to physical activity.
Therefore if you really aim to lose a few pounds, you have to be true to yourself and count your calories correctly.
So What Kind of Calorie Deficit Should You Create?
As mentioned earlier 1 pound of weight translates to roughly 3500 calories. So if you intend to lose 1 pound per week you have to create a deficit of 3500 calories a week.
That would mean around expending 500 calories each day or decreasing your intake by 500 calories.
But is it so simple?
Well, I came across two really interesting studies that explored whether this predicted weight loss matches actual weight loss outcome.
One study states that this prediction is applicable only to those whose body fat is greater than 30 kg and not for those who have low initial body fat.
The other study demonstrated that actual weight loss was less than what was actually observed.
Now, why should the results differ!?
Factors to Decide the Number of Calories?
A number of external and internal factors influence your daily calorie requirement.
1. Basal metabolism rate
Yeah, we usually tend to blame this one, when we see that person who eats a lot but gains no weight.
Basal metabolic rate or resting metabolic rate is the energy utilised by an individual in fasting and resting conditions.
Different organs and tissues in humans have different metabolism rates.
A number of factors affect BMR such as: genetics, body fat, exercise, calorie restriction, age etc.
However, it is not true that higher the metabolism lower the weight.
In fact, obese individuals have a high metabolic rate which reduces when they lose weight. (Read Is Metabolic Rate Linked To Weight Loss?)
2. BMI
BMI is the weight of an individual divided by height. Body composition such as weight and height affect the metabolism rate.
Therefore most equations use height and weight as variable parameters to calculate required calorie intakes.
However, BMR can also differ by 20% in individuals of the same size.
3. Lean mass percentage
Lean body mass or muscles are metabolically active tissue. It accounts for a decent proportion of your BMR.
People with greater muscle mass have slightly high metabolism rates than normal individuals.
Amount of muscle mass is controlled by factors like genetics, age, and gender.
However, by exercising you can increase your metabolism rate and in turn increase your muscle mass and lose body fat.
4. Age
A child would require more calories for growth and development.
Similarly, an adult would require more calories than the elderly to match their active lifestyle. As we grow older our metabolism slows down.
Also, our physical activities reduce. As we age, muscle mass gets replaced with fat mass reducing our energy requirement.
Therefore as we age our calorie requirement lowers.
However, we can alter this by maintaining an active lifestyle despite of our age.
5. Gender
Men require a higher calorie intake than women. Also they are larger in built than women.
An adult man tends to have lesser body fat than an adult woman and 10-20% more muscle.
Muscles are metabolically active tissues and hence require energy or calories for their functioning.
Therefore an adult man’s calorie requirement is 10-20% higher than that of an adult woman.
6. Physical activity
Even activities like mowing a lawn, playing with children or simply standing requires energy.
A person with a sedentary lifestyle would tend to have a lower calorie requirement than an active person.
This is why athletes or those who go to gym tend to have a higher calorie requirement and generally a better appetite than that of an average individual.
The reason why exercise is so vital for obese individuals is that it raises metabolism rate which is reduced in response to dieting and low-calorie intake.
7. Medical conditions
Certain metabolic conditions are responsible for your calorie intake. Genes at times play a role in this.
Inherited metabolic disorders can sabotage your weight loss efforts.
Uncontrolled appetite is a symptom of Prader Willi syndrome. Thyroid malfunctioning can also lead to weight gain.
In such cases, you require to treat obesity as well as the medical condition simultaneously as both serve as a risk factor to each other.
Calculating Your Calorie Requirement for Weight Loss
There are a number of equations that have been defined to calculate daily calorie intake based on most of the factors mentioned above that can be accounted for mathematically.
It is difficult to decide which equation is the best and accurate.
Here are few approximate calorie requirements for individuals that are pre-calculated:
| Male Female | ||||||
| Age | Sedentary | Moderately active | Active | Sedentary | Moderately active | Active |
| 18 | 2400 | 2800 | 3200 | 1800 | 2000 | 2400 |
| 25 | 2400 | 2800 | 3000 | 2000 | 2200 | 2400 |
| 30 | 2400 | 2600 | 3000 | 1800 | 2000 | 2400 |
| 40 | 2400 | 2600 | 2800 | 1800 | 2000 | 2200 |
| 50 | 2200 | 2400 | 2800 | 1800 | 2000 | 2200 |
| 60 | 2200 | 2400 | 2600 | 1600 | 1800 | 2200 |
| 70 | 2000 | 2200 | 2600 | 1600 | 1800 | 2000 |
| 76+ | 2000 | 2200 | 2400 | 1600 | 1800 | 2000 |
Once again I would like to mention that these are rough estimates for adults of average height and weight.
For a more accurate estimate check out:
http://www.cnpp.usda.gov/sites/default/files/usda_food_patterns/EstimatedCalorieNeedsPerDayTable.pdf
You could follow this chart and identify the calories you need to take to suit your prolife.
So you can count your calories and limit it to this value in case you find yourself consuming more.
You could calculate your personal calorie deficit but calculating this can get somewhat complicated.
Here are some great tools which can help you calculate a suitable calorie deficit and also aid in predicting weight loss outcomes are:
http://www.pbrc.edu/research-and-faculty/calculators/weight-loss-predictor/
http://bwsimulator.niddk.nih.gov/
These are scientifically recommended as better alternatives to the 3500kcal rule and involve a more personalized approach in determining a calorie deficit.
How to calculate the number of calories I consume each day?
For this, start maintaining a food journal. Make 4 columns.
- In the first column mention the food you consume.
- Then go to http://nutritiondata.self.com/ and determine the calories for specific serving size and. Write it down.
- Then note the servings you consume.
- Finally, multiply the number of calories with a number of servings you take divided by unit serving size.
Here is an example: Now to find the calorie of a medium sized apple.
- Go to http://nutritiondata.self.com/ and search for apple. You will get a list of apple food products. Select apples, raw with skin ( http://nutritiondata.self.com/facts/fruits-and-fruit-juices/1809/2)
- Choose your serving size for example 1 cup slices-109 grams That amounts to 57 calories.
- Now estimate the serving size you consume maybe ½ a cup. So that would be 28.5 calories.
- That's it! Keep estimating calories for each item and add it up.
How to tackle your calorie deficit?
There are two ways by which you can deal with the calorie deficit:
A] Start burning more calories through exercise
If you see the earlier mentioned table, an active person requires more calories.
Therefore if you increase your physical activity, then you can take care of the extra calories.
However you need to lose weight, so you need to exercise a little more that takes care of the calorie deficit and burns extra calories and fat reserve.
This is a list of physical activities that can be feasible enough for you to perform in order to burn the extra calories.
|
Exercise type |
Calories per hour |
| A] Sedentary activities | |
| Lying down or sleeping | 90 |
| Sitting quietly | 84 |
| Sitting and writing, card playing | 114 |
| B] Moderate activities | |
| Bicycling | 174 |
| Ballroom dancing | 210 |
| Light housework, cleaning | 246 |
| Walking 2mph | 198 |
| C] Vigorous activities | |
| Aerobic dancing | 546 |
| Weight training | 756 |
| Basketball | 450 |
| Football | 498 |
| Swimming (45 yards/min) | 522 |
| Scrubbing floors | 440 |
| Jogging (6 mph) | 654 |
They are estimates of calories burned every hour by a 150 pound person
Adapted from: William D. McArdle, Frank I.Katch and Victor L. Katch, Exercise Physiology: Energy, Nutrition and Human Performance; Melvin H. Williams Nutrition for Fitness and Sport
B] Reduce your calorie intake by calorie deficit
Minus the calorie deficit from your daily intake and make this your new goal.
Stick to this new level each day and if ever you miss it, compensate in the next occasion. Here are a few ways you can implement this plan:
- Have more proteins. It promotes satiety and it is low on calories. Also more calories are spent to digest it.
- Another way to control appetite is to eat fruits and vegetables. They are rich in fibre and high on volume which makes you feel full.
- Stop consuming sugar sweetened beverages and fruit juices.
- Avoid foods that rich in trans fat. Have healthy fats like omega 3 fatty acids.
- Switch to a healthier cooking oil like coconut or olive oil.
- Watch the serving size. Food chains are happy to serve you a large serving size so keep an eye on that.
- Maintain a food journal and let this be your Holy Grail till you attain your weight loss goal.
Although you are reducing your intake, be careful that you do not exceed your limit. A diet going below 800 calories a day is not acceptable. Also once the goal is achieved, don’t change your attitude but strive to maintain it.
Conclusion
There is no exact number of calories that one should consume when attempting to lose weight.
A calorie is not a calorie.
That is every calorie gets utilised through a different biochemical pathway so it gives different amounts of energy.
Also, external factors such as gender, physical activity, and age are at play.
Therefore even the calculations we have mentioned are approximate and will differ from person to person.
However, they will be close to actual results so you can use them as a reference while designing your own plan.