In 2016, more than 1.9 billion adults were overweight, and of these, over 650 million were obese. Many people are working on keeping their weight under control, but their success is hard won.
Today we’re sharing what science can tell about why it is so hard to lose weight.
Firstly, why is fat even bad?
Fat itself isn’t bad, it’s just the way our body stores the energy in case of emergency. Unlike glucose and other forms of carbohydrates that react with oxygen and release energy in the cells, fat molecules are more stable and much harder to break down. That's why Mother Nature uses fat as a long-term energy warehouse.
For thousands of years, humans were totally fine with this: every so often there was a period of hunger, a plague, crop failure or just a bad luck at hunting. In short, food supplies were not stable. During all those years, people didn't have equal access to food resources. The main advantage of being 'upper class' was being able to eat a lot (and get fat). That's why back in the old days, it was considered more fancy to be round since it was an obvious indicator of wealth.
And then the 20th century happened. People managed to invent many different ways to make food cheap, such as industrialization, pesticides, fertilizers and more. Local farmer’s markets gave their place to chains of groceries stores, family restaurants turned into McDonald's. Big industries learned what sold better and worked to making food fatter, sweeter and saltier than ever.
At first, it was incredibly fun to eat so cheaply and tasty anytime you want, but the results were not long in coming. Since 1975 obesity has nearly tripled. Now, most of the human population lives in countries where being overweight and obese kills more people than being underweight. Obesity increases the risk of other diseases, such as type 2 diabetes, high blood pressure, atherosclerosis, heart diseases, some types of cancer and overall mortality. The good news, obesity is preventable.
Why do some gain while others stay slim?
There are many different factors that impact our weight, such as genetic, environmental factors and lifestyle choices.
Our main energy expenditure (60-80%) belongs to basal (resting) metabolic rate (BMR) over which we have almost no control.
Basal metabolic rate shows the energy expenditure for our body to do it’s basic functions, like breathing, regulating body temperature, digesting food and other hidden metabolic processes. BMR depends on genetics, the ratio between lean muscle and fat tissue in the body, sex and age. Science can't yet say exactly what impacts the metabolic rate or how to speed it up.
Also, some genes can impact our eating behaviours, such as the feeling full, craving sugar, and sensitivity to bitterness.
Overeating might be also a compensatory mechanism for emotional stress or a low quality of life. It’s simple: since eating is crucial for humans, evolution made sure we enjoy it. That's why when we eat, we receive a dopamine reward and feel pleasure. If there is nothing else to do and we are bored, we may eat even when we are not hungry.
Why is it so hard to lose weight?
It sounds so easy: to lose weight you need to burn more calories than you consume. All you need to do is to eat less and move more. But in practice, it doesn't work exactly this way.
First of all, losing weight is against our nature. For millions of years, evolution has been teaching our bodies to store energy (in fat) and gain weight. Even though today this mechanism is a bit outdated, it still has control over our behaviour.
This explains the next obstacle: that diets don't work because they restrict us from eating some foods, which send a signal to our brain similar to starvation. None of these fad diets that preach us to say 'no' once and forever to carbs, or fats, or sugars are efficient in a long-term period. These diets may show quick results, but then the weight bounces back as soon as a person drops off a diet and comes back to their regular eating habits.
Also, exercises isn’t too helpful in losing weight. Physical activity can only burn off 10-30% of your daily calorie intake, while your main energy expenditure belongs to your basal metabolic rate. Training cannot be used as a 'punishment' for eating some extra calories. Also, training hard makes us hungry and gives us an excuse to eat as much as we want, which also can lead us to overeat.
NB: we are not saying though that training and physical activity is completely futile.
Don't drop the dumbbells!
How to know if someone is overweight or obese?
The easy (but not very precise) way is to calculate your body mass index (BMI). The formula is a person's weight in kilograms divided by their height in metres squared. The healthy BMI range is between 18.5 and 24.9.
A BMI between 25 and 29.9 indicates overweight, of 30 and more – obesity.
BMI does not apply to children, pregnant women and heavy-weight athletes.
Another measurement of a healthy body is the waist-to-hip ratio (WHR). It helps to see if one's fat is mostly gathered around the abdomen or in the hips. When most of the weight is carried around the midsection (an apple-shaped body), it indicates a higher percentage of visceral fat (around internal organs) and may lead to a higher risk of obesity-related diseases. If a person carries more of their weight in the hips and thighs (a pear-shaped body), it's easier on their health.
To calculate one’s waist-to-hip ratio, divide waist circumference to the hips circumference. According to the World Health Organization (WHO), a healthy WHR is 0.9 or less in men and 0.85 or less for women.
How to get back in shape?
As you see, it's not easy and there is no magic diet, nor a set of exercises that will fix everything overnight. Nevertheless, there is some advice we can give.
1. Calculate your personal energy intake.
Firstly, calculate your basal metabolic rate (BMR). There are different formulas, but they provide similar results not to mention that this estimation is very general. You can use the online calculator or do it manually using the Mifflin-St Jeor equation.
- For men: BMR = 66 + (13.7 x weight in kg) + (5 x height in cm) - (6.8 x age in years)
- For women: BMR = 655 + (9.6 x weight in kg) + (1.8 x height in cm) - (4.7 x age in years)
My result for this estimate is 1353 calories approx. This is my basal metabolic rate, how many calories my body needs every day just to keep functioning. If I cut my calorie consumption below this level, it may cause serious health problems. That’s why doctors never recommend lowering one’s calorie intake below BMR or 1200 calories, whatever comes first.
With your BMR you can calculate your everyday energy expenditure. It depends on your activity level, which also can vary day by day.
Use these factors to calculate your average calorie expenditure.
- Sedentary = BMR x 1.2 (little or no exercise, desk job)
- Lightly active = BMR x 1.375 (light exercise/ sports 1-3 days/week)
- Moderately active = BMR x 1.55 (moderate exercise/ sports 6-7 days/week)
- Very active = BMR x 1.725 (hard exercise every day, or exercising 2 xs/day)
- Extra active = BMR x 1.9 (hard exercise 2 or more times per day, or training for a marathon, or triathlon, or having a physically hard job).
My recommended calorie intake falls between 1623 calories and 2097 calories. This is how much do I need to eat to maintain weight. Now, to lose weight, I would need to consume less energy than I spend (but not less than my BMR).
2. Start logging all the foods you eat in a day.
Use calorie tracking applications, they have information about most foods. This may be very boring, but it’s also pretty eye-opening; we tend to underestimate or overestimate the number of calories we consume.
Note about calories:
This exercise will show you roughly how much calories you consume. Meanwhile, we don't know exactly how many calories there are in each serving we eat. Moreover, how many calories you eat is not as important as where they come from. 50 calories from Coca-Cola have a different impact on your health than 50 calories of spinach. And yes, you'd better choose spinach!
3. Start building healthy eating habits.
Make sure you have all the macronutrients and micronutrients you need (protein, fat, carbohydrates and vitamins), eat slow carbs rather than fast ones, choose a wide variety of foods, try new ones every so often, don't forget about veggies.
Watch the triggers that cause overeating: having big gaps between meals and letting your hunger out of control, eating alone or while watching TV or scrolling through media on a phone, feeling stressed or unworthy, not sleeping enough. Make a plan for how to avoid these triggers.
4. Don’t starve yourself.
5. Keep yourself active.
If you don't like the gym, go for a walk, play with a dog or just clean your room – even easy everyday activities help.
6. Seek professional help.
Weight issues often have psychological underground and it’s not easy to deal with them all alone. Look for a healthcare professional who will help you to cope with emotional stress, set goals, build healthy habits and keep up your motivation. Over the long-term, getting a specialist’s help yields better results.
As you see, the problem of being overweight is bigger than it looks. It requires more knowledge from trainers and nutritionists and certainly more empathy and understanding from the people around us.
To know how your genetic or gut bacteria composition impacts your risk of being overweight,
take Atlas DNA and Microbiome tests.
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