How much harder is it for an overweight person to exercise?

Factual Questions
21

So here’s a related analysis I worked out recently.

Let’s suppose you wanted to lose weight. The only method known to work is you must expend more calories than you consume.

How can you do this? Well, one way would be to work out your basal metabolic rate, and then, with the help of a tool like My Fitness Pal, eat less than your daily estimated metabolic consumption.

How much less? Well, it seems that the difficulty is more or less proportional to size of the daily caloric deficit. -100 calories you probably would barely notice, -1000 calories you’ll probably feel hungry most of the day. (unless you use hunger reducing drugs)

Well, what about burning those calories off with exercise? This is actually counterproductive.

Case A: Your BMR is 2500 kcal per day. You eat 1500, making the count -1000. You will lose almost 2 lbs per week.

Case B: Your BMR is 2500 kcal per day. You eat 2000 but do 500 calories of exercise each day, making the count -1000. You will lose almost 2 lbs per week, but you also have to exert the mental effort to perform the exercise.

Either A or B you feel just as hungry, but in the B case you also had to do effort to exercise. B is mentally harder to do than A, and you are not losing weight any faster. (and this is true for almost any set of numbers you can make up. You could also exercise in case A, or just eat even less)

Does it mean you shouldn’t exercise when losing weight? No, you should, but for health reasons (and the scientific evidence is in favor of a relative modest amount of exercise each week, nothing that would burn 3500 calories weekly). It is not making you lose weight faster. The weight loss is coming from not eating.

22

It is true that to lose weight you need to consume fewer calories than you expend at rest and through light and vigorous activity.

But while it is good to simplify these discussions, it is difficult to keep complexity when needed. If you eat more calories to cover all expended during exercise, you won’t lose more weight. But this does not have to happen, and the discussion is much complicated by:

A) The protein/fat/carb composition of calories

B) When nutrients are consumed in relation to exercise, affecting storage and partition

C) Whether the exercise builds muscle; the goal of losing fat and losing weight are different

D) How efficient someone is at the exercise

E) The degree of non-vigorous exercise (e.g walking a dog) which may not stimulate appetite in the same way

F) The length of time on the diet may change the basal metabolic rate as bodies evolved to survive and find efficiencies when there is less food, eg: reduce activity levels.

23

A is correct because if you are restricting calories, the calories you do consume need to have enough protein and essential vitamins and minerals.

B, C, D, E, F have little relevance to none.

24

They’re all pretty relevant, some more than others. But I guess we’re not going to agree on this. Life goes on.

25

Well, I’ve read that B is bullshit because time of feeding doesn’t actually matter much in clinical trials. Just total calories, as expected. C is irrelevant and wrong, if you are at a caloric deficit you lose weight, you will never gain it. Recomping is rather difficult when at a severe deficit. D is irrelevant, the deeper the deficit the hungrier you will feel. E is probably not too relevant, most likely long term hunger is the same regardless. (even if the exercise suppresses hunger for a few hours the person will feel it later). F is limited, if the body had unlimited throttling no one would die from starvation.

Most likely life doesn’t agree with you.

26

A. The protein composition makes a difference due to its thermic effect, it takes more calories to burn it. Protein is often more sating/filling as well. The fat composition makes a difference since the body does not turn fat into sugars, which are preferred by the brain and may affect insulin levels.

B. Exercise and nutrition trials are often underpowered or not designed for specific populations. But the work of John Berardi shows a benefit to consuming carbs just before, during or just after a workout. It’s also why eating large meals before bedtime is not recommended. In fact, eating the same amount of food, but early in the day (large lunch, small dinner) by itself results in less weight gain, since calories are more likely to be used than stored. Not all studies show an affect, but enough do.

C. Many people who want to lose weight would be happy if they looked like The Rock or were less fat and more buff. Muscle weighs more than fat and it is possible to gain muscle and lose fat with a good exercise program and diet. Your analysis is not bad but is too simple and minimizes the effect exercise can certainly have on improving body composition and weight loss as well.

D. Exercise efficiency matters. For climbing the stairs, a larger person might initially find it difficult. In a mechanical system, it can be difficult to start moving (static friction) and keep moving (dynamic friction). A biological equivalent means it is harder for a heavy person climbing steps to start moving and keep moving so they use more energy than simple equations would say. Once you get good at running 10 km races, it is surprising how few calories that burns.

E. If appetite always depended on calorie deficit, no one would lose weight. But people do. Cutting weightlifters and fighters do it predictably using known sports nutrition principles. This includes nutrient timing, cycling carbs and activity levels and paying attention to macronutrient profiles.

F. Peoples bodies do adjust to lower intake levels over time. This makes weight loss tougher than anticipated. The basal metabolism rate changes and this makes a difference to how long one might need to reduce calories. I agree a small reduction over more time adds up, though.

You don’t need to agree with me. I’m willing to argue once to educate people. Sometimes I’m wrong. Sometimes it isn’t worth feeding trolls, or looking for a consensus. Life agrees with me just fine.

27

A. Cents not dollars. If you’re eating at -1000 it doesn’t matter if it’s really -900 or -1100

B. Cents not dollars

C. If you want to look like the rock, you first need to stop being obese, and then you need to take anabolic steroids and combine this with high dietary protein and exercise. In that order.

D. Cents not dollars

E. Cents not dollars

F. A person’s body cannot make a -1000 calorie deficit into neutral or a surplus.

The flaw in all your analysis is that you are focused on negligible effects and missing the forest. The thing that actually matters is maintaining a large caloric deficit. If you can do that, you will lose weight rapidly. I have done this personally with a mix of protein drinks as they seem to have the maximum satiety:calorie ratio (about 4-6 hours satiety for a mere 100-150 calories) and a drug that suppresses appetite as a side effect. (it’s taken off-label by many physicians and people in silicon valley)

Once you are no longer overweight, if you want to get buff, well, if you’re under 25 and male and your father had big muscles, you can lift weights, going for increased lifts and eat a lot of protein. If not, you are going to probably either need to lower your expectations (Hollywood muscle requires steroids) or you’re going to need to obtain some synthetic testosterone of some type and inject it.

28

And the problem with your analysis is that it is simply not true exercise isn’t an important factor in losing weight or improving body composition. Diet is more important, but hardly everything.

But most people eat a horrible diet, and could make smaller and beneficial changes: eating more vegetables, reducing portion size of unhealthy snacks, eating less sugar and pastries, giving up non-diet soda, drinking less alcohol.

All it takes to improve at lifting weight and get strong is to start to do it, to make an effort to slowly increase weights or reps, and to consistently do it. No special genetics or drugs required. I don’t really have anything more to discuss with you.

29

Just focusing on calories to lose weight is typically insufficient since it doesn’t address the mental desires and compulsions around food and eating. It would be like telling a smoker to just smoke less or an alcoholic to just drink less. While those techniques will work in a theoretical sense, they often fail in the real world because the person struggles to control their urges.

Just answering the title of the thread “How much harder is it for an overweight person to exercise?”, it is typically much more difficult for the overweight person to exercise and it has nothing to do with the activity. Although the added weight is definitely a factor, the real difficulties are often overcoming the mental struggles. An overweight person will likely have many issues to deal with such as lack of motivation, self-doubt about their ability, criticism from friends and family, high levels of discomfort, etc. The thermodynamic difference of the activity is trivial compared to the difference in how a fit person approaches exercises versus an overweight person. Someone who works out 4x per week can do a long, strenuous workout without any internal issues to overcome. But an exercise newbie may have long internal discussions with themselves just trying to get out the door for a short walk. It is much easier mentally for a fit person to do a 1000 calorie workout than it is for a sedentary person to do a 100 calorie walk.

If someone is just starting out, they should primarily be focused on overcoming their lack of motivation. For the first 6-8 weeks, they should exercise on a fixed schedule without wavering. Set up fixed times 3x per week where they exercise. Don’t be so concerned about the level of effort or what activity is done. The important thing at first is to develop the habit of exercise and minimize the self-defeating behaviors which cause someone to quit. Over time exercise will be come a habit and will be much easier to do on a regular basis.

30

Actually, High Intensity Interval Training (Tabata etc.) is very effective at fat loss and aerobic conditioning, it is “high grade” cardio for very short periods, and climbing stairs can be an effective form of interval training.

31

The op? Someone actually cares about answering a GQ op? Huh. Wonders never cease!

It is a interesting question to try to answer, and yes the psychological is very real … but not what I think the op was asking about.

FWIW I’ve been mulling it around some more.

In terms of work being done the answer is the physics work and the op is indeed accomplishing the work of carrying 280 pounds up and down those flights, lots more than a 150 pound coworker is carrying. And that is a very valid answer.

And our op produces that work with less perceived effort expended compared to what 150 pound coworker would experience carrying that same total weight, even one who has been climbing stairs for a while (so has muscles well adapted for that activity). Put 130 pounds in a backpack on that coworker (or a 130 pound teenager carried piggyback style) and that coworker would struggle more getting up and down than our op would.

Of course that is both because that a while a significant portion of the op’s weight is fat, there is also a fair amount of the op’s weight that is muscle mass adapted to carrying that mass around, and because the mass in a backpack (or teenager) is not distributed in a way that makes carrying it as efficient.

That perceived effort (sing/talk test as one simple way to keep track) would fairly tightly follow the actual amount of metabolic work being done, which could be measured in a lab condition as the amount of oxygen consumed per minute which in turn correlates with calories expended.

But there is no clear formula to quantify that based on the weight information alone.
As to all the hijacks. Yeah simplistic assumptions lead to simplistic conclusions.

Calculated estimates of BMR and RMR based on body weight alone, even BMI alone, are +/- huge amounts, often reported as 20%, and sometimes much more (in comparison with the gold standard of indirect calorimetry).

RMR varies in response to body weight and composition changes and in response to sorts of exercise done. So even if an accurate RMR was obtained at the start it changes in a nonlinear fashion that is hard to predict, inconvenient to measure, and impossible to calculate.

Calories listed for foods are often very off from their net metabolic impact. A decent discussion of how that happens here but yup, often off by as much as 25%, with the real net to the body calorie impact of higher protein and fiber foods being overestimated.

No question that exercise impacts body composition to great degree (% body fat and how much fat is located in the most health damaging areas), has less impact on total weight loss per se, is of tremendous impact on health regardless of weight loss, and is a key part of maintaining a weight loss achieved.

Not going to go through all those letters but slavish attention to calculations (even if the numbers going in were good, which they are not) misses the key confounder: the role of the brain in all this, and I am not talking about “will power”. Not the psychologic as much as the neurophysiological. The brain is the boss of our metabolism and the brain responds to both the pleasure (“hedonic”) value of food, and its ability to give a sense of having had enough (“satiety”). Any given person will be able to achieve and maintain weight loss better eating a larger proportion of foods of moderate hedonic and high satiety values and relatively little of high hedonic and low satiety level. The former includes higher protein and fiber foods, the latter more highly processed crap. Good review here.

32

Which is why one of the best pieces of advice I’ve heard re. food is “learn to enjoy what you’re eating; if you’re not enjoying what you eat, stop”. Did wonders not just for a then-extremely-obese coworker but for everybody in the team. The second key piece was “eat when you’re hungry (even if it’s not supposed to be ‘a time to eat’), do not eat when you’re not hungry (even if it’s somebody’s birthday)”.

33

As a fat person myself, I can state that those of us who have Frequent Discount cards at Big & Tall stores are likelier to have bad backs, knees and ankles, which has to figure into this. OTOH, serious athletes seem prone to at least two of those three in their later years.

34

One of my ballet teachers told us about dessert: “You really only taste the first three bites. After that, you are just mechanically shoving food into your mouth, and gaining only more calories, never more enjoyment.”

By and large my observation is that she was correct. This knowledge doesn’t erase the instinctual urge to continue consuming a high-calorie food source, but it really helps the brain override the instinct when I have words for what is happening, and can watch for it.