Weight loss myths: discussing cause and effect

B2
90 min
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Think about these questions before watching. Share your ideas with a partner.

  1. When people decide they want to get healthier or lose weight, what are the first things they typically do, and why do you think these are the most popular strategies?
  2. Consider the common saying, 'You can't outrun a bad diet.' What do you think this means, and to what extent do you agree with it based on your own experiences or observations?
  3. Besides weight management, what are some of the most significant mental and physical benefits of regular physical activity? Describe a time you personally experienced one of these benefits.
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Watch the video carefully. Pay attention to the main ideas and key details.

Video script72 segments · click a timestamp to jump

We have this idea that if we want to lose weight, we join a gym on January 1st, we start

working out regularly, and eventually we’ll slim down.

Well, here’s some bad news. I read more than sixty studies on this, and

it turns out exercise is actually pretty useless when it comes to weight loss.

Dr. Kevin Hall at the National Institutes of Health has done some of the most important studies

on exercise and weight loss We need to rebrand exercise … exercise isn’t

a weight loss tool per se, it's excellent for health is probably the best single thing

that you can do other than stopping smoking to improve your health.

But don’t look at it as a weight loss tool. Exercise will definitely help you live a longer,

happier life…. It’s just not the best way to lose weight. And the reason has to

do with how our bodies use energy. You may not realize it, but physical activity

is actually a tiny component of your daily energy burn.

There are three main ways our bodies burn calories.

These include your resting metabolism, so that's how much energy your body burns just

for its basic functioning, just to keep you alive, basically.

The other part of energy expenditure is the thermic effect of food, and that’s just

how much energy is required to break food down in your body.

The third part of energy expenditure is physical activity.

For most people, physical activity - that’s any movement you do, only accounts for about

10 to 30 percent of energy use. So the vast majority of energy or calories

you burn every day comes from your basal or resting metabolism, over which you have very

little control. While 100% of your “calories in” are up

to you, only up to about 30% of your “calories out” are in your control.

One study found that if a 200-pound man ran for an hour, 4 days a week for a month, he’d

lose about 5 pounds at most, assuming everything else stays the same.

And everything else doesn’t stay the same! Researchers have found we make all kinds of

behavioral and physiological adaptations when we start increasing the amount of exercise

we’re getting every day. For one thing, exercise tends to make people

hungry. And I'm sure you know the feeling: you

go for a spinning class in the morning, and then by the time you eat breakfast you're

so hungry you maybe double the size of the portion of oatmeal you normally eat.

There's also evidence to suggest that some people simply slow down after a work out,

so if you went running in the morning you might be less inclined to take the stairs

at work. These are called “compensatory behaviors”

-- the various ways we unknowingly undermine our workouts.

Researchers have also discovered a phenomenon called metabolic compensation. As people start to

slim down, their resting metabolism can slow down.

So the amount of energy you burn while at rest is lower.

That means this bar might shrink as you start to lose weight.

There’s still a lot of research to be done, but one study from 2012 is particularly interesting.

They went out into the middle of the Savannah in Tanzania to measure the energy burn among

a group of hunter gathers called the Hadza. These are super-active, lean hunter-gatherers.

They’re not spending their days behind a computer at a desk.

And what they found was shocking.

What we found is that there was no difference at all.

So even though the Hadza have a much more physically active lifestyle, they weren't burning any more

calories every day than adults in the

US and Europe. Somehow the energy they used for physical

activity was being offset or conserved elsewhere. So how do they stay slim? They don’t overeat.

We can undo the calories that we burn off in exercise pretty quickly.

It would take about an hour of running to burn off a Big Mac and fries.

You’d have to spend about an hour dancing pretty vigorously to burn off three glasses

of wine you might drink with dinner. An hour of cycling really intensely on exercise

bikes to burn off about two doughnuts. That’s why exercise is best seen as a healthy

supplement for a strategy that’s focused on food.

But despite extremely high obesity rates in the US, government agencies continue to present

exercise as a solution ... as do companies with a real interest in

making sure we keep eating and drinking their products.

Since the 1920s, companies like Coca-Cola have been aligning themselves with the exercise

message. The idea here is that you can drink all these

extra bottles of soda as long as you work out. But as we're seeing, it doesn't work like that.

Actually burning off those extra calories from a can of soda is really, really hard.

We have an obesity problem in this country, and we shouldn't

treat low physical activity and eating too many calories as equally responsible for it.

Public health policymakers should really prioritize improving our food environment

to help people make healthier choices about what they eat.

It's not impossible to lose weight through exercise,

it's just a lot harder. And we need to recognize how that works.

If you do go to the gym, and you burn all these calories, it takes you a long time to do so

and you put in a great amount of effort,

you can erase all of that in five minutes of eating a slice of pizza.

Relative magnitude is actually quite surprising, and most people don't fully appreciate that.

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Answer these questions in your own words. Support your answers with evidence from the video.

01According to the video, what is the primary benefit of exercise, and why is it not considered an effective tool for weight loss?
Sample answerThe video says the main benefit of exercise is for your general health, helping you live a longer and happier life. It's not an effective weight loss tool because physical activity only accounts for a small part, about 10-30%, of the total calories we burn each day.
02What does the video mean by 'compensatory behaviors', and in what ways can they undermine a workout?
Sample answerThey are actions people take, often without realizing it, that cancel out the effects of their exercise. For example, a person might feel extra hungry after a workout and eat a larger meal, or they might be less active for the rest of the day because they feel tired.
03What was the surprising discovery from the study of the Hadza people, and what does it suggest about the connection between an active lifestyle and daily energy use?
Sample answerThe surprising discovery was that the very active Hadza people burned the same number of calories daily as less active adults in the US and Europe. This suggests that our bodies might adapt to high activity levels by conserving energy in other ways, so being more active doesn't automatically mean you burn more total calories.
04Why does the video argue that some companies have promoted a misleading message about exercise and diet?
Sample answerThe video argues the message is misleading because companies suggest that you can eat or drink their unhealthy products as long as you exercise to 'burn it off'. This is misleading because it takes an enormous amount of effort and time to burn the calories from even a single unhealthy item, which makes it an unrealistic strategy.
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Key vocabulary

Vocabulary
These expressions will help you discuss the topic of health and fitness more precisely.
Examples
A quick fix — a simple and fast, but often temporary, solution to a problem.
Usage note: This phrase often has a slightly negative meaning, suggesting the solution isn't sustainable. Common phrases are 'look for a quick fix' or 'there is no quick fix'.
To take something with a grain of salt — to understand that a statement or piece of information may not be completely true.
Usage note: Use this idiom to express healthy skepticism about claims you hear. For example: 'Take social media fitness advice with a grain of salt.'
To fall short of expectations — to fail to achieve the result that was hoped for.
Usage note: This is a useful, slightly formal way to talk about disappointing results. For example: 'The weight loss from just exercising often falls short of people's expectations.'
In the long run — over a long period of time in the future.
Usage note: Use this to contrast short-term actions with their future consequences. It's often used to give advice: 'It seems hard now, but you'll be healthier in the long run.'
To have a knock-on effect — to start a process in which one action causes a series of other, indirect actions.
Usage note: This is perfect for talking about cause and effect. It can be positive or negative: 'Sleeping better has a knock-on effect on my ability to concentrate.'
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Decide if each statement is true or false. Correct the false ones.

01Metabolic compensation, as described in the video, is the tendency to eat more after a hard workout.
02The expert in the video claims that exercise is the single most effective action a person can take to improve their health.
03According to the video, you have full control over your 'calories in' but only partial control over your 'calories out'.
04A study mentioned in the video concluded that a 200-pound man who runs four hours a week could lose about 5 pounds in one month.
05The video claims that you would need to run for about an hour to burn off the calories from two doughnuts.
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Complete the sentences with words from the box. One word is extra.

Word bank
01Many people are looking for a quick for their health problems, but sustainable change takes time and effort.
02If you set unrealistic weight loss goals, you're likely to fall of your expectations and feel discouraged.
03While crash diets might seem effective, in the long , they often lead to more health complications.
04Improving your sleep schedule can have a positive effect on your energy levels, mood, and diet.
05You should take claims about miracle diet pills with a large grain of and consult a doctor instead.
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Choose the best answer based on what you heard in the video.

01According to the video, which component is responsible for the largest portion of a person's daily energy expenditure?
02What does the video suggest about the historical messaging from companies like Coca-Cola?
03What is the main recommendation the video gives to public health policymakers regarding the obesity problem?
04Which of the following is NOT mentioned in the video as a way the body adapts to an increase in exercise?
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Cause and effect in health

The video discussed the relationship between exercise and weight loss. Now, let's explore some other cause-and-effect relationships related to health and well-being.

Match the beginning of each sentence with its correct ending.

Drag or click to match
Definitions
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Discuss these questions with a partner. Try to use vocabulary from the lesson.

  1. The video suggests that the common belief about exercise for weight loss is a myth. To what extent do you think the fitness industry is responsible for promoting exercise as a quick fix for weight loss, and should their marketing be taken with a grain of salt?
  2. Thinking about your country, what are the most common public health messages about diet and exercise? Do you feel these campaigns are effective, or do they often fall short of expectations by oversimplifying the issue?
  3. The video emphasizes that exercise is not the best tool for weight loss but is crucial for overall health. What small, sustainable lifestyle changes do you believe could have a positive knock-on effect on a person's well-being in the long run?