Be healthy at any weight?
The world is obsessed with fad diets and weight loss, yet few of us know how a kilogram of fat actually vanishes off the scales.
Even the doctors, dietitians and personal trainers surveyed shared this surprising gap in their health literacy.
The most common misconception by far, was that fat is converted to energy. The problem with this theory is that it violates the law of conservation of matter, which all chemical reactions obey.
Some respondents thought fat turns into muscle, which is impossible, and others assumed it escapes via the colon.
So if not energy, muscles or the loo, where does fat go?
The enlightening facts about fat metabolism
The correct answer is that fat is converted to carbon dioxide and water. You exhale the carbon dioxide and the water mixes into your circulation until it’s lost as urine or sweat.
If you lose 10kg of fat, precisely 8.4kg comes out through your lungs and the remaining 1.6kg turns into water. In other words, nearly all the weight we lose is exhaled.
This surprises just about everyone, but actually, almost everything we eat comes back out via the lungs. Every carbohydrate you digest and nearly all the fats are converted to carbon dioxide and water. The same goes for alcohol.
Protein shares the same fate, except for the small part that turns into urea and other solids, which you excrete as urine.
The only thing in food that makes it to your colon undigested and intact is dietary fibre (think corn). Everything else you swallow is absorbed into your bloodstream and organs and, after that, it’s not going anywhere until you’ve vaporised it.
Why the body fights weight loss
The control of weight is based on the balance between calorie consumption and the energy spent during our day to day living. The brain’s weight control centre is in an area called the hypothalamus.
The hypothalamus integrates the incoming signals from the body (such as hormonal signals) and other parts of the brain and then control weight by affecting hunger and satiety.
It also communicates with other parts of the brain that control metabolism (such as the pituitary gland and sympathetic nervous systems). This complicated and fine-tuned system determines a “weight set-point” which is the weight the body is accustomed to and then works to defend it by fine tuning our metabolism and our calorie consumption.
Energy consumption is divided into the resting metabolic rate (about 70% of all energy used), the energy consumed in processing the food we eat (thermogenic metabolism) and exercise based energy expenditure.
A few studies have outlined the result of moderate weight loss. The body defends against weight loss by drastically reducing the energy expenditure.
The body also goes into a sort of “starvation mode” to protect against lean body weight loss by preferentially depleting different energy stores including glycogen, fat and then eventually muscle.
The body spends a large percentage of energy in the maintenance of organ function, even when asleep.
In obese people, the resting metabolic rate significantly increases, perhaps to try to prevent further weight gain.
Unfortunately, when you lose weight, the opposite happens and the body’s metabolism turns right down.
This may occur through reductions in the active thyroid hormone (T3) and changes in the hormonal messages back to the brain promoting hunger.
A key finding in the above studies is the reduction in resting metabolic rate is disproportionately large, and potentially persists for long periods.
This explains why a return to a pre-weight loss lifestyle inevitably results in weight re-gain, and possibly more than was lost.
Only by maintaining a healthy lifestyle with calorie restriction of around 25% and exercise can we avoid the inevitable. The reduction in resting metabolic rate may be particularly problematic in people with severe obesity.
We all have eating habits and body shape simply don’t add up. While enjoying the unhealthiest of meals and a sedentary lifestyle, somehow they effortlessly retain a slender figure.
At first glance we may assume these slim people are healthy, but it’s not always the case. So if you don’t have weight to worry about, what’s the impetus for avoiding sweet or salty temptations and eating good, nutritious foods instead?
Healthy weight ≠ good health
Body mass index or BMI, the tool most often used to determine “healthy weight ranges”, was designed primarily to track the weight of populations.
While it’s a simple and useful screening tool when looking at groups of people, it’s not a good marker of individual health.
This is because BMI is a measure of our height and our weight, and the ratios of their combination.
But weight alone doesn’t discriminate between a kilogram of fat versus a kilogram of muscle, nor does it account for body shape and fat distribution differences relating to, say, ethnicity or gender.
Disclaimer: The information on this POST is not intended or implied to be a substitute for professional advice. The opinions expressed within this article are the personal opinions of the author. All content, including text, graphics, images and information, contained on or available through this article is for general information purposes / educational purposes only, and to ensue discussion or debate.
Thank you …Holidays are often a time of overindulgence and food-based regret. That’s partly because when people eat together, they tend to eat more.
But if you’re aware of the things that encourage you to eat more than you need – and perhaps more than you plan to – you might be able to nudge yourself towards eating less than you would otherwise.
Here are eight evidence-based actions you can take to actively control your food intake in the face of the abundant food on offer during the holiday season.
Cut down on processed foods
Reducing the energy density of foods can be an easy way to reduce the number of kilojoules you consume without giving up on the satisfaction of a filling meal.
Research shows people who replace processed foods with a more natural alternative find it easier to limit their intake and therefore maintain their weight or lose weight.
Clearly, advocating healthy lifestyles is one part of the solution, but education alone will not be sufficient. We need to enable those living with obesity to maximise their health and well-being, and [access treatment
Want to add word or two?
We also cannot ignore the role of the environment we live in. So, instead of debating fitness versus fatness, we need to shift from a focus on individuals to a focus on society. Then healthy choices – both activity and diet – can become the easy choices for everyone.
Your comment ….?
Although there should be no doubt that moderate exercise has a broad range of benefits, I don't think enough emphasis is placed in the quoted research on the obvious link between health and the capacity to stay healthy.
How much of the statistics are masked by people who are sadly saddled with an illness, and are therefore both less inclined to exercise and more likely to die (from the illness)?
Wrong question, perhaps. Not ''Can you be healthy at any weight at any point in time?'', but "Can you maintain long-term health at any weight?''
A heavy smoker can be objectively ''healthy'' before they develop chronic bronchitis, emphysema, vascular disease, lung cancer.
A morbidly obese person can be healthy before the develop osteoarthritis, hypertension, type 2 diabetes, coronary disease.
At any point in time, anyone can be ''healthy''. That doesn't mean that risky health behaviour, continued long-term, won't have long-term effects.