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Why Is 1200 Calories a Day Important When Dieting

Why Can't I Eat Fewer Than 1,200 Calories on My Diet?

If you're determined to lose weight, choosing healthier foods and counting calories is essential, but you might be surprised that slashing calories to the bare minimum isn't the ticket to weight-loss success. Here's some information and advice on the issue from a board-certified physician who practices in Southern California.

Dear Doctor,

I decided this is the year I will lose that 25 pounds I gained after college. I am dieting and counting calories. I heard that you shouldn't eat fewer than 1,200 calories a day, and I am wondering why? Can you please explain, because I thought I should eat as little as possible.

— Dieting For Real This Time

This is a great question, and I'm sure that there are other readers who have decided on a similar weight-loss resolution as you have! I commend you on your weight-loss resolution.


The principle behind weight loss is simple: you either have to burn more or eat fewer calories. To lose weight, you need to create an energy (or calorie) deficit by eating fewer calories, increasing the number of calories you burn through physical activity, or both. Typically, what is recommended as the safest method is a combination of eating fewer calories and burning calories through physical activity. While you do report that you are dieting and counting calories, you do not mention that you are doing physical activity and exercise, which, as mentioned above, is so important in the safe weight-loss equation.

Determining a safe daily calorie deficit can be difficult because every person is different when it comes to baseline metabolism, body size and composition, sex, age, and level of physical activity. What is easy to determine, however, is the fact that 3,500 calories equals about one pound of fat. Therefore, you have to burn 3,500 calories more than you take in to lose one pound. For example, if you cut 500 calories from your diet every day, you would lose about one pound a week. Or, if you are physically active, you can eat 250 calories less every day and burn 250 calories per day with your workout. Ideally, you do not want to lose more than one to two pounds per week, which means a safe calorie deficit would be to burn 500 to 1,000 calories per day through a reduced-calorie diet AND exercise.

Determining a safe minimum amount of daily calories can be difficult as well for the same reasons listed above. However, extreme restriction of consumed calories can significantly slow the metabolic rate, and hinder your weight-loss goals. The American College of Sports Medicine states that you shouldn't send signals to your body to conserve calories by detoxing or fasting. They recommend that women should eat at least 1,200 calories per day, and men should eat at least 1,800.

The reason that the metabolic rate slows with prolonged dieting of less than 1,200 calories per day is a chain reaction of physiologic responses to the stress associated with such a restricted diet. Your body initially adapts to the stress of low caloric intake by engaging the "fight or flight" stress response, which has several negative consequences, despite you seeing lower numbers on the scale. The "fight or flight" response stimulates the breakdown of muscle in order to supply the body with enough fuel (glucose) to maintain the blood sugar levels in the absence of sufficient dietary calories. This "fight or flight" stress response will eventually wear out, thus slowing the metabolic rate to compensate for what the body perceives as starvation.

In summary, there are three guidelines to safe and effective weight loss: aerobic physical activity, gradual changes in eating habits to encourage a lifestyle change, and a slow weight loss of one to two pounds per week.

Hopefully, your weight loss questions have been answered with the above information. As always, you should consult with your physician before starting any weight-loss or exercise program. Also, if concerned with dietary or nutritional aspects of weight loss, consulting with a licensed nutritionist or dietitian may be of benefit. Good luck with your continued weight loss!

Dr. Nicol's posts are for informational purposes only and should not be considered medical advice, diagnosis, or treatment recommendations. Click here for more details.

Join The Conversation
ShaninaHarris ShaninaHarris 2 years

Did you have surgery?

Bonnie15254519 Bonnie15254519 3 years
I had the lap band by one if the most recommended doctors in the country in 2007.... I lost considerably, over 100lbs! I have started to gain... For years I was a devoted runner and have completed 9 half marathons and one full... Now that I am a single mother, full time graduate student, full time employee and a half time employee, I don't have time to run as much. My doctor blames running and says I didn't change my diet, I only ran and once my body gave out, I would gain unless I changed. No, I didn't eat 600-800 calories a day when running. I ate much much more. But now I don't get to run and eat 800-1200 and I am gaining. As a previously boarder line diabetic and obese woman I am terrified at my future outcome. I am criticized and lectured when I go to the doctor about what I am eating..... I teach yoga, juice, try to eat healthy but don't always succeeded, yet I am gaining rapidly. I need advise and help! If I stay at the 600-800 calorie, 60-80gram of protein a day, I still have zero results and I am miserable!!!!! Advice?
fritzlepretzel fritzlepretzel 4 years
i feel like everyone is freaking out about the 1200 calories per day suggestion. The author says AT LEAST 1200 calories which is the bare minimum. They aren't telling you how much to eat. It all depends on the individuals needs as well. This is only a guideline. It also says to consult your physician. This is not an in depth written work about the specifics- take it for what it is- a helpful and informative article about how to spark weight loss!
Dare-You-To Dare-You-To 4 years
Isn't 1200 the bare minimum, assuming that you are just lying down not moving all day? Don't we need more if we're up and about, walking, and especially- EXERCISING as this article recommends? Prescribing the bare minimum to maintain bodily function is drastic and irresponsible, without considering other factors such as the person's activity level. Further, it isn't all about calories. What about where those calories come from? Real food or sugary junk? Eating less but still eating garbage doesn't send the right signals to your body either.
thehilside thehilside 4 years
Making healthier food choices that are satisfying and energizing is definitely key. Theres no need to starve yourself and then binge because of it and run yourself into the ground. In the long run, it is a permanent lifestyle change... not a diet! If everyone just focussed on being the best they can be and being healthy, then each individuals physique will fall in to place, just as it was designed to be!
Giuliana14787855 Giuliana14787855 4 years
The way the title and URL of this article is worded is incredibly irresponsible. Even though your article offers some (debatable) scientific research and advice for weight loss and calorie counting, the implication of this article is that 1,200 calories is a "magic" weight loss number, which is a very dangerous implication to make. Please consider being more mindful and less sensationalist in titling and promoting your articles. There's no real need to put an arbitrary calorie number in the title at all; the point of this article is to say that eating too few calories for one's own body will hinder them from losing weight. 1,200 calories is nothing but an arbitrary number.
annfran annfran 5 years
hello  is it healthy to do a diet that consists of having 2 shakes as a meal replacement. 1 for breakfast  1 for lunch and then an evening meal .  
LizAnderson410 LizAnderson410 5 years
Amber512 - that is so great! This article is just what I needed to read. Thanks, everyone!
sarlafrock sarlafrock 6 years
Actually, 3500 calories does NOT equal a pound of weight loss. Recent studies, like the one by my friend Kevin Hall at the National Institute of Health ( have proven this is not the case. This is an oversimplification. Calories in versus calories out is still true, but going negative by 3500 could mean MORE or LESS than 1 pound of weight loss. Check out the study!
amber512 amber512 6 years
No diet, but a lifestyle change. Exactly! I am so glad that I found those (four, holy cow!) four years ago. I have lost and kept off over 90 pounds by making small changes to my lifestyle that I can keep up with for a lifetime.
OCgirl OCgirl 6 years
I have been using the MyPlate tool for the last six months and have lost 20lbs. You enter your current weight, how many lbs you would like to lose per week and your activity level. Then, it calculates the amount of calories you should net every day. Once you do this, you can track your food intake and exercise on MyPlate either on your computer or on the iPhone app. It's so easy to use! The thing I learned by tracking my calories is that I had no idea how many I was consuming before even though I thought I was making smart choices. The biggest change I made is that I no longer buy my lunch out--I always bring homemade food to work--which has easily cut out 500 cals in my diet. I also try to eat all other meals at home during the week and then I enjoy myself on the weekends. Also, I increased my exercise from 4-5 times per week to 6-7 times per week. It definitely is a lifestyle change that you need to be committed to!
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