A recent study published in the New England Journal of Medicine looked
at 7 common myths about obesity that both the public and healthcare providers
hold as true, and looked to see if research could actually back them up. The results may surprise you, but remember
that fighting obesity is an individualized battle – work with your healthcare
provider to find what works for you! Here is a summary of the study findings:
Myth 1: Small changes in diet
and/or exercise will result in more long-term weight loss.
The study suggests that the advice of eating 500 calories less a day or
burning 500 calories more a day does not necessarily mean a 1 pound weight loss
a week, mostly because this does not take body composition into account. By
this they mean that if you are exercising more and putting on muscle as you
burn fat, your net weight loss will be less because muscle weighs more than the
same volume of fat.
Bottom line: Before getting discouraged that the number on the
scale is not going down, think about the possibility that you have replaced fat
with lean muscle, which is heavier but healthier.
Myth 2: It is important to set
realistic weight loss goals, to avoid frustration and reduced weight loss.
The study authors could not find anything to prove that this was true,
and even mentioned studies that showed that people sometimes actually lost more
weight with more ambitious weight loss goals.
Bottom line: There is no conclusive proof of what type of weight
loss goals work better. Think about what motivates you more, and follow that.
Myth 3: Slow, gradual weight
loss has better long-term outcomes than large, rapid weight loss.
The study could not find any big differences between slow, gradual
weight loss and large, rapid weight loss in long-term outcomes (keeping the
weight off, continuing to lose weight, etc.). They could not say why some
people lose a lot of weight quickly while others lose weight more slowly, so it
does depend on the person.
Bottom line: This study only looked at weight loss success over
the long term, and not effects on health. It is best to follow a weight loss
plan under the advice of a health care provider to make sure you do not cause
more harm than good in your weight loss efforts.
Myth 4: People have to be ready
to make changes if they want to succeed in weight loss.
The authors found that the amount of readiness a person has does not
predict the amount of weight loss or ability to stick to the weight loss plan.
One thing to keep in mind though: people who signed up for these weight loss
studies were already ready to make changes – otherwise they would not have
signed up in the first place!
Bottom line: People who at least think about trying to lose
weight could potentially lose more weight than people who have not thought
about it at all. It is hard to get studies to prove otherwise since signing up
shows a minimal amount of readiness to begin with.
Myth 5: Physical education in
school is important in helping reduce and prevent childhood obesity.
The authors mention studies that showed the current physical education
curriculum in schools is not making an impact on obesity in children. More
research needs to be done before any real conclusions can be made.
Bottom line: While more research needs to be done, what little
evidence is out there seems to show that the physical education programs
currently used in schools are not enough to combat childhood obesity.
Myth 6: Breast-fed infants have
a lower risk of obesity later in life.
The World Health Organization (WHO) has published research to show this
as true, but it has been found to be biased. Other research without this bias
has not been able to prove that breast feeding an infant reduces the chances of
the infant becoming obese later in life. More research needs to be done to
definitively say one way or the other.
Bottom line: Though the jury is still out on whether breast
feeding helps prevent obesity, the many other proven benefits of breast feeding
still stand, and should be encouraged.
Myth 7: Sex can burn 100 to 300
calories per session.
For the average person, this is probably not true. The average bout of sexual activity lasts
about 6 minutes, and the study authors estimated that in that time, a man in
his early to mid-30s would burn only about 21 calories. Of course, such studies
cannot take other factors into account such as type of activity, so it is
important to take that into account.
Bottom line: It is difficult to say exactly how many calories
are burned during sex, so it probably should not be counted upon as a major
source of exercise and weight loss...sorry y'all!
The study goes on to discuss other presumptions about obesity and
weight loss, such as skipping breakfast, yo-yo dieting, and snacking, but does
not give good information on these, thus making them not worth mentioning at
this time. It should be known that many of the study authors also have
connections to various parts of the food industry and food organizations, so
there is a potential for bias in this research. Overall, the idea of
re-examining commonly held beliefs about obesity and weight loss is a good one
– it will encourage healthcare providers and the public to base their decisions
on science, and will help prevent a lot of misinformation in society.
- Nami
Citation:
Casazza K, Fontaine KR, Astrup A, Birch LL, Brown AW, Bohan Brown MM, Durant N, Dutton G, Foster EM, Heymsfield SB, McIver K, Mehta T, Menachemi N, Newby PK, Pate R, Rolls BJ, Sen B, Smith DL Jr, Thomas DM, Allison DB. Myths, presumptions, and facts about obesity. N Engl J Med. 2013 Jan 31;368(5):446-54. doi: 10.1056/NEJMsa1208051. PubMed PMID: 23363498; PubMed Central PMCID: PMC3606061.)