Ask the Dietitian: Am I Eating Too Few Calories to Lose Weight?

Sidney Fry, MS, RD
by Sidney Fry, MS, RD
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Ask the Dietitian: Am I Eating Too Few Calories to Lose Weight?

We cover a lot of ground when it comes to nutrition at MyFitnessPal. Some of the topics can be tricky and deserve further explanation from our experts.

That’s why I’m here! We asked you for your burning questions on our Facebook page, and we got more than 140 responses. Every few weeks, I’ll pick a few of your questions to answer in detail. This installment is all about calories.

Cutting back on calories is the primary approach most people take to meet their weight-loss goals. But it is possible to take calorie restriction too far, ultimately making weight loss more difficult by slowing your metabolism? When your body senses you’re not getting enough nutrients from food, it may slow down your metabolism as protection against the possibility of starvation.

As a general rule, most people need at least 1,200 calories to feed their everyday activities, metabolism and bodily mechanisms. People who are more active and exercise regularly usually need more.

A diet with too few calories may not only hinder weight-loss efforts, but could also make it difficult to meet your daily vitamin and mineral needs, and have an overall negative impact on your health. And depending on how much you are exercising, too few calories means not enough fuel to execute optimal calorie burn.


Protein is a very good thing — it regulates blood sugar, preserves muscle strength and is essential in helping the body build and repair cells, muscles, organs and skin. It also takes more energy to digest than sugar and refined carbohydrates and keeps us full. Most of us have little trouble meeting the minimum amount; the average American consumes about double the amount of protein we actually need. Eggs, chicken and the occasional protein shake are good, but make sure you’re looking beyond just protein and getting in enough plant-based foods like fruits, veggies and whole grains, too.

As far as too much, there are no rigorous long-term studies that can give us an exact answer. But what we do know is this: There does seem to be a limit on how much protein the body can use at a given time. One study from the Journal of the American Dietetic Association found that, on average, subjects who ate 90 grams of protein in one meal got the exact same health benefits as those who ate 30 grams.

When you’re meal-planning, consider the whole package: fats, good carbs, vitamins, minerals and other nutrients found in whole foods (something protein shakes and powders often lack). Aim to include foods that deliver some healthy fat and fiber with each meal, and go for variety. Add fish and plant-based proteins like legumes, whole grains and nuts to your diet, too.

Here’s a great tool that’ll give you a rough idea of target protein intake, based on your individual needs.

Got another burning question for me? Keep them coming! Ask away in the comment section below, and keep up with our Facebook page for more opportunities to Ask the Dietitian.

About the Author

Sidney Fry, MS, RD
Sidney Fry, MS, RD

Sidney is a two-time James Beard Award-winning food and nutrition writer, editor and mom based out of Birmingham, Alabama. A registered dietitian with a passion for research and being proactive about health, she loves to eat, write, run and create simple, tasty meals with whole-food-based approach. Find out more from her website, Instagram or Twitter.


30 responses to “Ask the Dietitian: Am I Eating Too Few Calories to Lose Weight?”

  1. Avatar Heidi Lee Hoerman says:

    I’m somewhat appalled that this article gives credence to this mythical version of “starvation mode.” Although one’s metabolic rate may decrease with loss of weight do to reduced movement, supporting less flesh, etc., it never reduces such that you lose the ability to drop pounds. Read the recent science!

    • Avatar Billy McGrail says:

      Wtf are you talking about? You clearly don’t understand starvation mode and no it’s not upon shedding weight. It’s upon trying to shed weight but putting yourself in too much of a caloric deficit. Yes it DOES happen. When you don’t fuel your body it responds by storing more fat as fuel as well as breaking down muscle…Study gluconeogenesis. Muscle is what raises your BMR. Don’t post ignorant comments on topics you don’t understand.

      • Avatar Joel Prowting says:

        No you clearly don’t understand energy balance. Look at the studies on individuals on very low calorie diets (800kcals). Theyve been found to lose more weight than more moderate diets in obese. Your body has to get energy from somewhere, if it’s not food, then it’s your body (adipose tissue, muscle tissue, glycogen etc). Yes metabolic rate decreases during a calorie deficit, but it’s still always possible to lose weight. Hence people starving to death… also, I don’t think you exactly understand what gluconeogensis is yourself

        • Avatar Billy McGrail says:

          People who starve to death die of “malnutrition.” Please, seeing as you’re so brilliant enlighten me on gluconeogenesis. Tell me when your stores are depleted and you aren’t in a catabolic state where your body takes the amino acids from to convert into glucose? Please tell me approximately how many calories 1lb of muscle burns daily? Please tell me how breaking down your muscle to convert to energy whilst not providing sufficient energy (kcals) does not slow down metabolism? 100% of individuals who go on a strict caloric intake for extended periods of time will gain weight back 10 fold once a normal diet is reintroduced. You cannot function at optimal levels on such a deficit, it will effect the individual in multiple ways. One being brain function. Sure Dr.A got lost a lot of weight but he was also weak as shit and died as a fat dude. Wanna lose weight and be as healthy as possible. EAT

          • Avatar Joel Prowting says:

            You’re completely right about gluconeogensis breaking down muscle to create new glucose (it also uses glycerol, which is found in fat!). Interestingly, each 1lb of muscle only burns an extra 6-10 calories per day (Wang et al., 2011), the brain, liver, organs etc burn way more per lb. The only way to lose weight is to be in a sustained calorie deficit. Whether that occurs through calorie tracking, low carb, low fat, intermittent fasting, added exercise etc, the underlying reason is due to a calorie deficit. That’s undisputable. The question being asked here is whether calories can be set *too low* to stop weight loss. And the answer is no, see below the references to the Minnesota starvation study. Yes, if you’re in a severe deficit your functionality isn’t optimal, of course, your body is in a state of stress. But the reason people stop losing weight isn’t because magical starvation mode starts piling on fat, it simply doesn’t work like that

          • Avatar Arthur Barnard says:

            You are completely right Joel, and the reason I know this is that I have seen my wife go through this when she had gastric bypass surgery. the 1st week before the surgery she had to be put on a protein shake and liquid diet( wasn’t to bad she did well), the 2nd week right before her surgery she was on a pure liquid diet( that was hell). When she finished with her surgery was on a liquid diet for another week which she did great on. the 2nd week after she was done started to add protein shakes into the diet. By the 4th week she started to slowly add regular food to her meal. It was a long point but she was on a very large deficit caloric intake. and lost over a 100 pounds within 6 months. she still has a very low calorie intake.

      • Avatar Heidi Lee Hoerman says:

        I’ve read the recent science. Metabolic rate may decrease but not so much as to prevent weight loss.

        • Avatar Joel Prowting says:

          I agree Heidi, I was supporting your point

        • Avatar Constantin Miguel Chen says:

          People forget that the original Minnesota study stated that “starvation mode” kicked in at an extremely low bodyfat percentage, and even then BMR dropped by 200 calories max. The way this dietitian phrased it, it would sound like they completely loss the ability to lose weight.

        • Avatar Dave Zotzman says:

          That’s great that you’ve read stuff about it, try experiencing it. I’ve had gastric sleeve surgery for weight loss and during my recovery period, I was lucky to be able to eat 800 calories per day. My weight loss stalls unless I can get in at least 1400. As soon as I drop b below that, I get very tired, sleep a lot and around the 1000-1100 calorie per day, I actually put on weight. That is starvation mode. The body goes into shutdown (tired all the time) and conserves every bit of food energy that it can (stalling of weight loss, or even gain).

      • Avatar Daniel Beale says:

        This makes no sense whatsoever. The human body doesn’t have the ability to suddenly become more fuel efficient without the trade off of significantly reduced energy levels, if it did it would do it all the time – see how evolution works.

        “When you don’t fuel your body it responds by storing more fat as fuel” How and why would this happen? Your body doesn’t have enough fuel yet is somehow magically able to find enough fuel to keep your body running as normal AND store fuel as fat?
        Where is this fuel coming from?
        Before you answer “from muscle” fat is almost twice as energy dense as muscle so even if it was breaking down muscle to store as fat (which it isn’t, what exactly would the purpose of that be?) you would still be losing weight.

      • Avatar mia says:

        i came on here to get advice about things i dont understand about weight loss, it would be nice if the people who respond to others questions would not be so mean, with that attitude i dont want your advice.

  2. Avatar Jen Ullett says:

    I’m surprised this article didn’t mention the fact that weight loss stalls could be a factor of inaccurate tracking – eyeballing instead of weighing your food for example.

  3. Avatar Mimi says:

    I wish you would have went into further detail about too much protein consumption and how it does have a negative side effect if consumed over a long period of time. Too much protein can make the blood acidic and the body will remove minerals from the bones to deacidify the blood. Also, most people know it can affect the kidneys. HIgh levels of protein consumption should be done in short periods and then have periods of rest and consume only the amount to maintain.

  4. Avatar Stella Barbone says:

    “When your body senses you’re not getting enough nutrients from food, it may slow down your metabolism as protection against the possibility of starvation.”

    Could you post a reference for this claim? It seems pretty remarkable. It must be a very new study and I would be interested to read it.

    • Avatar Constantin Miguel Chen says:

      It’s an old study, from WWII, called the Minnesota Starvation Experiment. In that they discovered the body enters into a “starvation mode” where BMR drops by about 200 calories when the body reaches a point that it cannot lose any more weight at around 1-5% bodyfat.

      If you’re not losing weight because of lower caloric intake, it’s more likely from either underestimating the amount of calories you’re eating (easy to do), or your eating habit freezes weight loss (also easy to do).

      • Avatar Stella Barbone says:

        That study is badly misinterpretted in the context of routine calorie reduction for weight loss. The subjects began the calorie reduction part of the study at just under normal weight, were eating far less food, and getting far more exercise than an ordinary dieter. They were fed almost 2000 kcal less than their needed intake. The effects of reduced metabolic activity were not seen until the subjects were extremely underweight. There is no way that those results can be generalized to the overweight population that is eating at a modest calorie reduction aimed at 0.5-2 lbs per week.

      • Avatar Chris Gervais says:

        What do you mean “freezes?” I have been on about 900 calories for years and cannot lose a pound. I am going to a dietitian and that isn’t helping. Am I frozen? Thanks, Chris

      • Avatar Chris Gervais says:

        I forgot to mention I maintain a food diary here and do measure so I am quite certain I don’t eat more; except on rare occasions like holidays. Thanks, Chris

      • Avatar Chris Gervais says:

        Oh, yes: I am not sedentary but I am 66. What do you think?

  5. Avatar novo says:

    oh FFS, not this idiocy again. read the minnesota starvation study. men put on 60% of their TDEE (adjusted as their tdee dropped) for 6 MONTHS kept losing weight, until doctors decided they got dangerously thin. that was real starvation. how can someone on mfp allow this kind of BS to be published is beyond me. it’s basic biochemistry, you can’t gain weight (other than water weight, i guess) on a long term caloric deficit.

    • Avatar Roger Gaytan says:

      I agree with you 100%. It’s completely flawed data interpretation. If people want to HINDER fat loss goals then continue to eat at maintenance and then add more because you exercised. Smh. I worked with dietitian for 1 year and I actually GAIN weight even though I was working out 2 times a day because she subscribed to this dumb bull crap method. I stayed that long because I figured they are a professional, surely they know more than I do. All I did was waste time and money.

  6. Avatar Natasha Gordon says:

    I am curious how I can breakway from being a prediabetic. This week i have kept my carbs below 75 but I am still hungry. How can I get full but also reverse prediabetes?

    • Avatar davedave12 says:

      you can snack on raw vegetables almsot anytime

      Protein satisfies — beans are complex carbs not the same as simple carbs i.e. sugar

    • Avatar Clint says:

      Reduce the carbs more. I stay below 30g of carbs daily. Lost weight, feel great and blood glucose is under control. It’s not easy but not as hard as one would think. You will probably have carb flu for a week or so but then you’ll see great results. (note this is for type2 prediabetic or diabetics). After you achieve control you can ease up on the carbs and maintain control.

  7. Avatar chrisJ says:

    Hi! I’ve been eating healthy for a while now and consume about 1,600 calories a day. Anything under that and I’m famished! I noticed that I’m eating almost 800 calories a day in fruits and vegetables and the other 800 in food (chicken, yogurt, milk, eggs, etc.). Is this okay to do? If so, then why would Weight Watchers tell their clients to eat as many fruits and vegetables as they want for zero points when I just ate 800 calories in fruits and vegetables!? If I was on Weight Watchers would I just count the 800 calories in food for the day since I’m not supposed to count the fruits and vegetables?

  8. Avatar Martin Scolden says:

    There is every possibility that you consume too much of

    protein. The fact is having a balanced diet in the right proportion is essential.
    That will equip you with the right calories of food class.

    I couldn’t agree less with you Sydney. Thanks for the piece.

  9. Avatar davedave12 says:

    are all the dietitians in Alabama this hot? got any healthy recipes with grits and lard?

  10. Avatar Dmember says:

    Did this article ever answer the question … “Am I eating too few calories to lose weight?” Or was that clever title just meant to draw us here?

  11. Avatar Sandy Wall says:

    Been overweight most of my life-topping out at 280. Down to 240 now eating lean meat, veggies, good fats like olive oil limited fruit because of sugars-NO bread, pasta or simple sugars. I’m at the gym 4 days a week doing the circuit or pf 360 and some treadmill. My hips keep me off the treadmill for extended periods. I try to maintain my calculated macros according to my size and exercise. I also keep a food journal. My weight loss has stalled but I haven’t changed my routine. Should I up my game at the gym, eat more, eat less???
    The macros I try to maintain are cals 1200-1500, carbs 60, protein 125 and fat 30. this is according to a macro calculator I used. I’ve heard many views on calorie deficit leading to starvation mode and stalling weight loss but as big as I am there seems to be plenty of fat already in storage. LOL. When I fast I definitely lose the pounds- not done intentionally, depends on my work schedule and not having time to eat. It’s all so confusing-I never know what to believe. Any advice would be greatly appreciated. I admittedly do not know the science behind weight loss. I know what’s worked for me but I seem to be stalled now. Maybe I’m underestimating my calorie intake?

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