As humans, it is our nature to analyse, find patterns, prove concepts and if not anything then we tend to generalize.
As side effects of these processes, myths are born.
Obesity is one such health concern that is bombarded with myths, presumptions and misconceptions.
And the rapidly changing and developing concepts regarding nutrition add to this burden.
However, a few researchers were kind enough to address such issues and bring forward scientifically based reasons as to why these well-established rules are just myths.
Top 10 Obesity Myths Debunked By Science
Today we are presenting 10 common myths about obesity as revealed in the following scientific commentaries:
- Casazza et al, Myths, Presumptions, and Facts about Obesity , N Engl J Med. 2013 January 31; 368(5)
- Chaput et al, Widespread misconceptions about obesity , Can Fam Physician 2014;60:973-5
And there are a few more which are not present in these reads but are clinically proven.
These are real eye-openers. In fact, you will be surprised as well as happy to read some of them.
1.The 3,500 kcal per pound for weight loss rule
The 3500kcal rule was developed on the idea that a pound of fat tissue stores approximately 3500kcal.
So decreasing 500kcal per day should lead to a loss of 1 pound of fat in 7 days.
Oddly this is not what happens in reality. Research shows that this rule results in a pretty modest weight loss compared to what it promises.
This is due to the fact that every individual’s response to changes in diet and energy expenditure in terms of body composition varies.
A good example quoted in the study goes like this: As per the 3500kcal rule predicts that a person who burns an excess of 100kcal each day by walking 1 mile will lose about 50 pounds in 5 years but in reality, the weight loss is only about 10 pounds.
3500 kcal rule is a good way to start your weight loss efforts but it definitely leads to an overestimation of subsequent weight loss.
What does this mean? The idea that cutting down 500 kcal per day will help you lose 1 pound of fat per week is inaccurate or rather an overestimation.
This is because every person’s body will react differently and also every individual has different energy requirements and expenditure which needs to be accounted for.
2. All calories are made equal
The concept ‘a calorie is a calorie’ is true with respect to thermodynamics but extrapolating it to human bodies and nutrition is pretty difficult.
Like carbohydrates provide you with 4kcal / gram but fibres despite being carbohydrates do not provide you with 4kcal since part of it is not digested.
Different macronutrients require different amounts of energy to be processed which is why protein is said to raise metabolism.
Low carb diets are said to be metabolically advantageous- more weight loss per calorie but then again some scientists feel that there could be other reasons for such rapid weight loss.
100 calories of low-calorie foods like fruits and vegetables is not likely to make you gain weight as much as 100 calories of candies or processed foods rich in trans fat. (100 calories is just an example.)
However, this does not discount the idea of calorie counting. The right amount of calories from the right foods should do the trick.
For scientific details on this topic refer to How Vital Is Calorie Counting For Weight Loss?
What does this mean? Diets of equal calories but differing in macronutrient composition bring about different results in terms of weight loss thus making it important to focus not only on the amount of calories but also on their source.
3. Slower the rate of weight loss better the end result
A number of clinical trials have reported that more rapid and greater the weight loss initially the lower the body weight at the end of a long term follow up.
One study quoted in the commentary compared rapid weight loss with slower weight loss on short term and long term end results.
It was found that rapid weight loss produced great short term results but in long term, there were no differences in results through both approaches.
Therefore researchers feel that recommending a slower rate of weight loss can interfere with the achievement of successful weight loss goals.
Also one can consider that rate of weight loss won’t really matter if you can sustain the weight loss with permanent changes in lifestyle (assuming that no health condition is responsible for obesity in that individual).
What does this mean? Slow gradual weight loss does not deliver any different results in long term in comparison to rapid initial weight loss.
4. Obese individuals have a slow metabolism
This is a widespread notion that overweight or obese individuals have sluggish metabolism compared to normal weight or slimmer counterparts.
Interestingly the equations that are used to calculate basal metabolic rate are a function of body weight and it is directly proportional. So the heavier you are the higher your metabolic rate would be.
A number of studies show that indeed obese individuals studies show higher metabolic rate and research also shows that upon losing weight individuals have a slower metabolism which impedes further weight loss.
However that does not mean that low metabolic rate does not contribute to weight gain.
It does. But it would not be right to generalize that all obese individuals have a low metabolic rate.
Low metabolic rate could be due to a disease or genetic factors and all obese individuals are not afflicted by it.
What does this mean? Not all obese individuals have a low metabolic rate. The more you weigh, the higher your basal metabolic rate will be.
5.Eat less and move more
The general idea is obesity is a result of lack of exercise and good dietary habits.
These are considered as the ‘big 2’ reasons behind the positive energy balance contributing to obesity.
More or less these two factors are true for obese people who are healthy otherwise. And most weight management programs are focussed on these two aspects.
But there are a number of other factors which heavily contribute to obesity and are commonly ignored.
Lack of sleep, medications, hormonal imbalance, psychological stress, health conditions etc are few of the reasons.
These reasons are as strong as the ‘big 2’ in causing obesity and overeating and reduced physical activity is a result of these underlying conditions.
Researchers feel that there is a growing body of evidence that lack of sleep can slow down weight loss.
What clinicians need to understand from this is that they need to consider the wide spectrum of causes behind obesity and rather than focussing on the ‘big 2’ alone, they should also attempt to rectify these underlying conditions.
What does this mean? Apart from diet and physical activity, there are number of factors that could cause obesity. In that case obesity would be a symptom of these conditions..
6. Diets work in long term
If losing weight was a hurdle, then maintaining weight is a Herculean task.
Scientific observation shows that 66% of the population that loses weight regains it within 1 year and almost all regain it within 5 years.
After successful weight loss, there are a number of metabolic and behavioural factors which interrupt weight maintenance.
Those who successfully maintain weight (approx 13 kg for a year) engage into a different lifestyle like eating low energy diets, practising intense physical activity and constantly monitoring body weight.
This behaviour can’t be imitated by most of the population.
Additionally if you resort to supplements or other weight loss aids alone, it is kind of obvious that the effect is going to be temporary.
Sustained weight loss with diet alone is possible for a few individuals but for a more realistic approach one needs to practise some behavioural changes.
What does this mean? A diet alone does not aid in weight maintenance. Successful weight maintenance requires a shift in behavioural aspects and this is what you should stick to. That would include a healthy diet, good eating habits and engaging in decent levels of physical activity.
7.The success of weight loss programs is measured in terms of the amount of weight lost
Would losing significant amount of weight be the only thing you would look forward to from an obesity management program? Research shows that focusing on weight loss as a measure of success is ineffective in creating healthier, slimmer bodies.
In fact it is kind of damaging as it can leave individuals preoccupied with food and body image, cause repeated cycles of weight loss and gain, lowered self esteem and social stigmatization .
Other criteria that should be included when describing success of a weight loss program should be improved overall health, greater self esteem, high energy levels and preventing weight gain.
What does this mean? Weight loss programs should focus on large goals such as improved health, increased self esteem in addition to achieving weight loss goals and these factors should be considered while defining success of a weight loss program.
8.Exercise brings about better weight loss than dieting
We have already addressed the idea that diet and exercise are considered as the ‘big 2’ behind obesity but there is no such thing that working on either one of them will result in greater weight loss.
It is extremely appealing and logically sound to think that physical activity involves burning of calories and hence will result in more weight loss than dieting.
But research shows that exercise alone results in a modest weight loss of approximately 2 kg.
One of the reasons behind this that exercise tends to increase appetite and does not lay down any dietary restrictions and this counteracts the calorie burning effect of exercise.
Still exercise helps get rid of harmful abdominal fat and fat of the trunk region.
What does this mean? Exercise does tend to burn calories but if you don’t change your eating habits or the kind of food you eat then the burning calories effect will be nullified. Exercise alone leads to modest weight loss but those who exercise regularly will reap numerous health benefits and are likely to be successful in maintain weight.
9.Obese individuals are less active than normal weight counterparts
This is a real common misconception not only in general public but also among health practitioners.
Obese and overweight individuals are thought to be lazy in comparison to than normal weight counterparts.
Firstly the truth is that most of us do not meet the physical activity recommendation as stated by health organizations.
Secondly it is never considered that probably an obese individual’s weight itself may interfere in his attempt to be physically active.
In fact it can even be demotivating which is why obese individuals tend to shy away from activities involving physical strain.
In fact a study in Canadian children demonstrated that obese boys burnt more calories per day and a similar observation was made in case of adults.
Scientists suggest that instead of focussing on burning calories we should now focus on reducing sedentary time.
What does this mean?
Obese individuals may be as active or even more active than their slimmer counterparts. However in some cases it may be their weight limits their physical activity. Research shows that when physical activity is translated in terms of BMI and calories expended, obese individuals do tend to burn more calories. The focus should shift from burning calories to reducing sedentary time.
10.Obesity can be combated with willpower to lose weight
This one is an absolute regular in case of obesity and it is pretty disheartening to hear it. Who would not want to lose weight and be fit?
The amount of weight loss differs for every individual even if they are following the same weight loss program or techniques and even with similar compliance.
For people who have already lost some weight putting more efforts in the same program will not always result in additional weight loss.
There are a number of compensatory mechanisms at play.
For example when you lose weight you experience a decrease in metabolism or energy expenditure which can reduce the effect of your weight loss efforts.
Identifying such compensatory mechanisms and finding ways to get around them such that results are delivered can reinforce an individual’s willpower.
What does this mean? Willpower is indeed a majestic form of energy but in each case individual results differ. Weight loss techniques that work for one might not work for the other. In that case it would be inappropriate to say that everyone with willpower can lose weight.
So these are the top 10 obesity myths which I feel it is high time we should accept as myths rather than facts.
The papers reveal a number of other such points and you can check out those papers for further details.
We should understand that obesity is not a choice and it is necessary to determine the root cause behind it. One size does not fit all.
Every individual responds differently to different weight loss interventions and efforts and adherence to those efforts results in successful weight loss, maintenance and a healthy body.