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Do You Know Your Calories?

As I have blogged before, obesity is the physical manifestation of positive caloric balance and trying to manage your (or your clients’) weight without understanding (or teaching your clients) calories is like trying to balance your bank account without understanding money.

Just imagine wanting to balance your bank account without any concept of how much money you make, what the bank charges to handle your money, and how much money you spend each month.

Similarly, trying to manage your “calorie account” without any idea of how many calories you are eating (or drinking) in relationship to how many calories your body actually needs is probably not the smartest way to go about managing your weight.

So do people with excess weight understand calories and do they have realistic perception of the caloric deficit required to achieve their weight-loss targets?

This question was addressed by Gregory Kline and Sue Pedersen from the University of Calgary, in a paper published in Diabetes Obesity and Metabolism earlier this year.

In this study, 130 subjects with type 2 diabetes participating in a weight loss trial were asked how much weight they would like to lose and to estimate the caloric deficit required to achieve this weight loss.

Notably, all subjects had previously received dietary teaching from a dietitian and a nurse at a diabetes education center.

While the desired weight loss ranged from 4.5 to 73 kg (average 26.6 kg), only 30% of participants were willing to estimate the caloric deficit required to lose their target weight.

Among participants, who dared estimate the caloric deficit required to lose one kilogram, answers ranged from 0.7 to 2,000,000 calories/kg (median 86 calories/kg).

Nearly half the subjects (47%) underestimated the total required caloric deficit to achieve their target weight loss by more than 100,000 calories!

Thus, as the authors note,

Despite attendance at a diabetes education centre, this population of obese individuals had a poor understanding of the quantitative relationship between caloric deficit and weight loss.

My guess is that many health professionals, who recommend weight loss to their clients, are probably not much better at estimating total caloric deficits than the participants in this study. I would imagine that few of the health professionals, who nonchalantly recommend that a patient go lose 50 lbs (e.g. before hip surgery), actually realise that they are prescribing a 175,000 calorie deficit (or almost the total number of calories that the average person would consume in three months).

This is why I maintain that a minimum degree of caloric literacy together with at least a basic understanding of calorie homeostasis is important for anyone trying to manage their weight and is definitely something I would expect of anyone recommending weight loss.

While regular readers of these pages will well appreciate that I certainly do not subscribe to the notion that weight management is simply a matter of calories in and calories out, I do believe that understanding calories is a prerequisite for any meaningful discussion about weight management.

Edmonton, Alberta

p.s. One kilogram corresponds to approximately 7,000 calories – one pound corresponds to approximately 3,500 calories.

Kline GA, & Pedersen SD (2010). Errors in patient perception of caloric deficit required for weight loss–observations from the Diet Plate Trial. Diabetes, obesity & metabolism, 12 (5), 455-7 PMID: 20415695


  1. For those of us wanting to figure out what the number of calories we need to consume to lose weight, what is the formula? I suspect I am not getting enough calories but don’t know how to calculate what I need.

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  2. Funny about the calorie estimation. When I was growing up (60s, 70s) magazines were full of “easy ways to shave 50 cal off your meal” with lists of foods. When did we become that math fearful?

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  3. @Jody: there are numerous calculators out theree on the Internet based on common formulas that take into consideration age, sex, weight, height, activity levels etc. But these formulas generally provide only a rough estimate and do not apply if you have already lost weit or are on any medications that affect metabolism.

    Another way to estimate caloric need is to measure what you are currently eating. If you are currently weight stable, then this is a good estimate of your current requirement. To lose one pound a week, wyoi would need to shave off about 500 calories from this.

    However, it is very important to note that the fewer calories you eat, the more attention you need to pay to the nutritional content of the food. So start by cutting the “empty” calories. If there are no empty calories in your diet, then you may benefit from meetinng with a dietitian befor reducing calories any further.

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  4. Fascinating book:

    What I Eat, Around the World in 80 Diets
    by Peter Menzel and Faith D’Aluisio

    80 people,including
    800 cal/day Kenyan herder, 2600 cal/day Canadian restaurant manager, 4200 cal/day Spanish bullfighter, 1600 cal/day man loosing weight to be able to have bariatric surgery …

    Some of the calorie counts are quite surprising to me – some smaller people eat more than I’d expect.

    Great pictures of the people, their food, their environment. Great commentary.
    I borrowed copy from library.

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  5. ps on “What I Eat” book: also includes:
    6500 cal/day Arctic hunter,
    12, 300 cal, overweight English “snacker mom”, on a binge day

    Amazing range of caloric intakes and types of food.

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  6. To be honest, for someone with a lot of weight to lose, those numbers seem very discouraging. The goal of cutting out 350,000 calories or even just 3.500 does not seem attainable. I think it’s more doable to just set a goal of eating 1200 to 1500 calories per day and know that that is a reasonable caloric intake for an obese woman trying to lose weight.

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  7. Dr. Sharma: I wish that you would stop propagating the myth that 3500 calories equals one pound of weight. This number came from Ancel Keys’ starvation and refeeding study using the voluntary calorie deficit of a small group of men who were conscientious objectors to war. The average was that 3500 calories equaled one pound of weight loss but there was huge variability in the actual numbers. These simplistic ideas in my opinion should not be propagated as we know that as one loses weight all kinds of systems come into play to protect the body from weight loss and it becomes harder to lose weight over time. I think it would be much truer to say that some people will lose weight easily and some will find it much harder. The key is to finding what works in each individual since not everyone responds the same. As a dietitian and someone who has previously been 40 lbs heavier I learned this the hard way. For years, I worked in diabetes and endeavoured to eat the high carb, low fat, frequent meal diet that we suggested to patients. It was not until I stopped eat as many grains and ate a significant amount of fat that I lost weight and have kept it off for 3 years now. This was without changing the amount of activity I did since I have always been active and speaks to a) how important diet is and b) to find a plan that works for the individual versus coming up with some calorie deficit number.

    I also think that knowing how many calories are in food relative to the amount we need in a day is relevant but what is way more important is paying attention to your body cues and eating when you are hungry and stopping when you are full, which is something nobody seems to talk about. Our bodies have this incredible ability to give us feedback about our food but it seems to me the medical profession, and my profession, continue to act as though knowledge changes behavior. While this is not fully untrue, it seems to me that we really need to change what we are exposed to daily in order to help to change what we do. With 50,000 items in the average grocery store, it is likely that the enormous variety and constant exposure to food will continue to lead to weight increases in the general public.

    Knowing how many calories you need to lose weight, or for that matter, how many are in a food focuses on the “head” part of the solution. What is truly missing is the emotional part of eating, the environmental set up for eating, the economic factors in eating and the social factors in eating, etc. It is no wonder we are so miserably ineffective.

    Take care and keep up the thought provoking articles.

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  8. Just depends on the time, and who is talking, and is it fat or body weight. Water makes up between 50 and 15% of the weight loss. The Quartermaster study found 4000C/Kg, Keys and Yudkin something similar with semi-starvation.

    To loose weight fast you will be in semi-starvation. watch you vitamins and minerals.

    This nice little N=1 puts it together. At day 4, 50% or 1800C/pound, by day 30, 3500C/pound.

    But I know nothing.

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  9. Perseverance is the most necessary characteristic for weight loss. The human body is only about 27 percent efficient at its best, depending on who you beleive. If we give up all sugars, grains, lubricants, and processed foods, the efficiency drops down a bit, giving an advantage. (Atkins advantage)

    According to Bernstein you need to hold your carb level steady at a low level, move your protein level up or down to gain or lose weight, and eat enough fat to not be hungry.

    Taubes says “Because it’s quite possible that the only meaningful way to lose fat is to change the regulation of the fat tissue, and the science of fat metabolism strongly implies that the best way to do that, if not the only meaningful way, is by reducing the amount of carbohydrates consumed and/or improving the quality of those carbs we do consume.”

    Taubes basically sets protein and fat and changes carbohydrate to control weight.

    Either method works for me, as long as the protein is about 1gm/kg of body weight, with associated fat, a few vegs, and get back to work. Watch your vitamins and minerals.

    I, personally, do not eat any sugar, grains, lubrication (manufactured oils) or processed foods. These mess up my blood sugar. Leaving those high calorie/low nutrition food out makes numerical sense and agrees with many diet gurus. Some people feel these are addicting, and insist on complete avoidance is easier for me than eating some and then stopping.

    But what do I know.

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  10. And yet, assiduously watching every penny does not pay off my credit card, healthy habits do. We know that it’s cheaper to bring lunch than go out, to take the subway than to pay for parking, to forgo drinking… It’s the same with food, we may not know the exact calories in a fast food sandwich or fries, but we know we’re better off without them. We know we’re supposed to eat: oatmeal for breakfast, salad for lunch, turkey for dinner. What more is there to know? I’m being facetious (or is it ironic?) since I am a mathematician, I count calories – I even count calories when I’m grocery shopping, on the theory that anything I buy I will eat. I know when a splurge will undo a day’s dieting or a week’s. But it’s not the knowing that helps me, it’s the tools to break my diet in small ways, to indulge in non-caloric things.

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  11. My guess that few understand how many calories are in what food would be surprising because so few think of a calorie as a price a price you need either for nutirent rich foods or pleasure rich fooods. Many people see that I am loosing weight and do not comprehend that in order to lose the extra weight that they want to lose that they must do the same. A calorie is basically a unit of measure that you must understand inorder to decrease you weight–I have gone to only having one serving of protein a day (eggs, meat, fish, ect) and have done much better on the weight lose front. Afterall there is protein in products other than meat. The most frustrating thing is the servers who insist on mamoth portion sizes and then they say “I want to lose weight to” they just dont get it–they can not maintain statuse quo and get different results. Thank you for the insight, it is as wide spreade as the reseach states.

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  12. Wouldn’t it be lovely if all we needed to be concerned with were simple calorie math! And the process of losing weight is, indeed, mostly math. Sadly, according to empirical research, only 3% of those who lose radical weight (more than 10% of highest established weight) can maintain those losses for five years (with precious little follow up after that). This is because the process of body regulation gets much more complicated as time goes on. Maintenance is much more difficult than loss (not that loss is a picnic — pun intended).

    All of that said, I disagree with Ms. Sawitsky above, about the importance of intuition because intuition becomes unreliable over time too. “Body feedback” takes into account lost weight, which the body doesn’t necessarily judge to be a great thing that should be maintained. To the contrary, if your body senses it needs to restore 50 lost pounds, it’s going to send you messages (intuition) that won’t support weight-loss maintenance. I call these messages “eat” impulses, because they differ from hunger, but they are real and do press upon behavior. Some people get relief from “eat” impulses by cutting grain based carbs, but this is not a universal reality for all of us.

    Fred gives too much credit to perseverance. Crediting perseverance leads to blaming the victim: “You just didn’t persevere, Sweetie.” Many conscientious, energetic, intelligent people regain lost weight. People cannot maintain losses based on cultural mythology and simple calorie math alone. I can’t sum it up in this small space, but suffice it that it is much more complicated math + perseverance.

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  13. Dr. Sharma:
    I agree we need to create awareness of the number of calories we consume, via food logs, however the intent focus on dieting and weight loss has perpetuated since I was young (I am 51) and there was no obesity epidemic. It occurred to me the intense focus and societal pressure to be thin has left many frustrated, angry, and with feelings of low self esteem because they cannot reach some mythical ideal.

    Let’s take a look at an overweight/obesity rate of roughly 64%. There are 3 main body or somatotypes, there are combinations as well but for the purpose of this response, let’s focus on the 3. Only one of these somatotypes is genetically predisposed to being thin, which means the other two types are fighting there own genetice. Three body types, 64% obesity/overweight, the rate of obese/overweight individuals is nearly 2/3 of the population, and 1/3 of the somatotypes is genetically predisposed to being thin.

    Could this high obesity rate be interpreted asa message from the 2/3 of the population that are tired of starving themselves, to reach an unrealistic goal that can’t be obtained? We still live in a consumer driven/need results fast/ all or nothing society. If 2/3 of the population believe they cannot reach the guidelines and are tired of trying to attain the unattainable, we have the opposite extreme, which is also not healthy because self care is totally discarded. Somewhere between trying to “slim fast” and giving up altogether there is balance. Finding balance is an individual determination and requires awareness of our total wellness, physical, mental, emotional, spiritual, environmental, and social.

    Finding balance in our lives is a process, and requires some amount of physical activity, but we need to start at the beginning. If all you can do is walk from one room to another, that’s what you do consistently, until you are able to go further, and so on. If you are unable to walk there are Tai Chi CDs, table top pedals, etc. or just move your arms around until that becomes to easy, and move forward from there.

    We need to slow down, be patient with ourselves and if we have a disordered relationship with food, money, etc. it’s OK to seek counseling. Another societal stigma is in seeking mental health assistance. Seeing a psychologist does not mean there is something “wrong’ with you or that you are crazy, it means, you are evolving, and want to move on from the past, flourish in the present and grow in the future by addressing all the hard wired gunk from societal, and familial sources and the judgments, and experiences we are individually subjected to, mainly from childhood.

    We are not children anymore, we are adults and have the power to make changes so we can achieve the peace, balance and happiness we deserve. We can disregard media manipulation, and make our own rules, set our own standards and still take care of ourselves.

    We are having a community event based on balance. The event is local but the materials and resources can be printed off the website.

    Thank you,

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  14. Hi, Dr. Sharma.

    Dr. Jeffrey Friedman and Dr. Linda bacon say “counting calories” is a complete illusion because the body can balance all of that far more accurately than we ever could. Our bodies weight regulation systems do not operate meal to meal, day to day or even month to month – it’s years. Our bodies weight regulation systems operate long term. Consider the millions of calories taken in , in 3 years. Who could possibly conciously balance that ? Studies from all around the world demonstrate when people are not actively trying to “control” their weight, they stay stable.

    Calorie counts on food labels are off significantly – like 12 % less.

    So for long term success the both of them feel ” calorie counting” is not effective at all, and that listening intently to signals of hunger and fullness ( intuitive eating) is a much, much better way to do it.


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  15. @Razwell: this post is not about counting calories – it is about understanding that calories count! I never ask anyone to count calories but rather to simply become aware of where they ‘lurk’. Friedman and Bacon are right that the body does a fair job, but there is a limit to how efficiently your body can regulate calories when you are eating an extra 500-1000 or more every day – especially from foods or drinks that you could easily cut out if only you knew that they had that many calories.

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  16. Hi, Dr. Sharma.

    Yes, I see your point. I understand your patients are not in the category of people who can get away with eating an easy extra 800 calories and not gain a thing. There are those naturally lean people ( one of them is in my own family) , but obviously your obese patients cannot.

    And I agree, it is a good idea, I think, to know where we “lurk”. As Dr. Jeffrey Friedman said, “We all should try to stay at the lower end of our setpoints ” (e.g. 8 pounds less or so)”

    I think standing most of the day, intermittent walking .intermittent lifting a bit etc, eating very nutrient dense and not distracted in front of computer or TV, and really listening to satiety intently , and not drinking our calories can contribute to keeping us at the lower end. 🙂 I think “NEAT” is far more important than formal exercise as far as keeping us a little leaner. The act of sitting itself for very long periods significantly turns off efficient fat burning, I hear.

    But I do realize true morbid obesity is a different animal, and what works for the large majority of slightly over fat people , might not work for the severely obese ( who probably have disregulation of a lot of things).

    Overeating way past the point of satiety ( super guy busting stuffed) is never good for health.

    Take care, Dr. Sharma , and thank you for the work you do. I respect yourself, Dr. Stephan Guyenet, Dr. Linda Bacon and Dr. Jeffrey Friedman , as all of you are genuine doctors and scientists. I am just an informed layman, but realize my own limitiations because of this.

    Best Wishes,

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