Have you been dieting for what seems like forever without seeing the results you’re hoping for? Maybe you’re even gaining weight and you’re frustrated, tired, and about ready to throw in the towel.
You may be asking yourself: Why am I gaining weight when I barely eat?
Could this be due to the way you have been dieting? Could the calorie restriction actually be backfiring and making you gain weight?
The short answer is: probably not. But we humans are complex creatures and a lot of factors can impact our weight and overall well-being. So let’s dive into how you achieve the weight loss you’re hoping for and what could be hindering your progress.
What the science says
When it comes to weight loss, the science is clear that any approach that puts you in a calorie deficit will make you lose weight.
A calorie deficit means that you consume fewer calories from food and drink than your body uses to keep you alive and active.
This makes sense because it’s a fundamental law of thermodynamics:
- If we add more energy than we expend, we gain weight.
- If we add less energy than we expend, we lose weight.
But this is where the simplicity ends.
How many calories you’ll need to achieve a deficit is highly individual and will change over time as you age, your activity level changes, your metabolism changes, and your body fat percentage changes.
You can calculate your daily calorie needs using this formula, but this should only be seen as a starting point as the calculation can never take into consideration exactly how effective your metabolism is.
To find out why you aren’t losing weight, we need to look at some of the factors that can affect your metabolism
Can eating too few calories decrease your metabolism?
The body is a very intelligent machine in the sense that it knows how to effectively regulate its many processes to support homeostasis (keeping a constant weight).
In the context of dieting and weight loss, this means that if you restrict your food intake too drastically, your body will simply decrease its metabolic rate so it is burning fewer calories.
Of course, if your body begins to burn fewer calories each day, then it is going to be far more difficult for you to lose weight, but the problem is even greater than that.
If you aren’t providing your body with the energy it needs to fuel your daily activities, then it will have to begin sourcing it from somewhere else. You might be thinking the first place it will look is your stored body fat, but it will also begin breaking down your lean muscle mass so it can be converted to glucose and burned for energy.
This result is a snowball effect, where you are holding less muscle, meaning your metabolism begins to dwindle even further.
A study of contestants from the TV show The Biggest Loser was that if you have achieved dramatic weight loss very quickly, you may find that you now have to eat significantly lower calories than your peers to even maintain your weight.
If you decide to cut calories, never do it too quickly. When you first start dieting to lose weight, the best thing to do is to cut around 300-500 calories daily from your regular diet, or your ‘maintenance calories’.
Cutting just a few hundred calories each day will enable you to lose somewhere in the region of 1 – 3 lbs per week, which is just about right to make sure you are predominantly losing fat and not muscle.
If your weight loss stalls for a week or two, then you can simply cut another couple of hundred calories or consider adding a little extra exercise.
Tracking your calorie intake for weight loss
Unfortunately, most people who are trying to lose weight underestimate how many calories they eat daily. When we look at scientific studies, they find that 18 to 54% of people underreport how much they eat, and in some subgroups underreporting is as high as 70%.
This doesn’t mean that people are lying, but more likely that it is very hard to estimate food intake, especially if you didn’t cook the food yourself.
One way of assessing if you’re measuring your food accurately is to use a food scale to measure your food and keep an electronic food diary such as MyFitnessPal or CalorieKing. I recommend using a food scale rather than cups and spoons as it’s more accurate.
Another pitfall when it comes to estimating calorie intake is that some people will be very restrictive during the week and then “let go” and not track or pay attention during the weekends. I’m personally all for a relaxed approach to dieting but if you end up significantly overeating during the weekend, you might essentially end up no longer in a calorie deficit overall.
Other reasons you might not be losing weight while dieting
There are several reasons why people struggle to lose weight. Tackling the underlying issue can be what you need to reach your weight goals.
Some conditions and drugs can make you gain weight
Some conditions including Cushing’s disease, polycystic ovary syndrome, and hypothyroidism can make you gain weight or make it very difficult to lose weight.
If you’re experiencing unexplained weight gain or have struggled with these before it’s worth discussing the issue with your doctor and maybe have your medication adjusted.
Drugs such as steroids and some antidepressants may also cause weight gain. Don’t stop taking your medications but discuss doses or alternatives with your medical team.
You’re dieting, but not for weight loss
Dieting and eating less is in reality very subjective. Dieting for some means only eating whole foods, cutting out specific food groups, or no snacks or sweets, eating a meal less than they’re used to, intermittent fasting, calorie restrictions, and the list goes on.
But the thing is that you can be doing any of those things and still not lose weight if you’re not in a calorie deficit.
Reducing your calories has also been shown to lead to people being less active. Remember, a calorie balance is a balance of how many calories your body needs and how many you consume, so a significant reduction in your activity could tip the scale and halt your weight loss.
It simply takes time
Another common reason why people report not losing weight despite reducing their calories is that they don’t give it enough time. Our bodies will do their utmost to hold on to our fat reserves and you often have to be in a calorie deficit for a while before you will see any meaningful weight loss.
You might see an initial large drop in your weight the first week, but that’s most likely water and waste and you can’t expect to see that type of weight drop week over week.
Lack of sleep
Aside from time, another factor that could be impacting you is your sleep patterns. Sleep deprivation is often tied to higher BMI, although the exact correlation is unclear.
Why undereating could be hurting your health!
If you do decide to continue eating very few calories, you should know that there’s a chance that you’re putting your health at risk.
When your body goes into starvation mode, you are at increased risk of both physical and mental complications, including
- Abnormally low blood pressure and slow heart rate
- Heart rhythm abnormalities
- Hair loss
- Brittle fingernails
- Loss of menstrual periods in women
- Dizziness
- Trouble concentrating
- Anemia
- Swelling in your joints
- Brittle bones
- Depression
Undereating can also often lead to an unhealthy relationship with food, obsessively thinking about food, and potentially eating disorders.
If you find that you’re still not losing weight despite being in what you perceive as a calorie deficit while measuring out everything you eat and drink, you should:
- Check in with your medical team for your annual physical and mention your weight loss journey
- Increase your activity to increase your calorie deficit
- Get enough sleep and reduce your stress levels to the best of your ability
bob
Hi, in the past I have been binge eating at night and gaining up to 2 pounds over night, then not eating the next and repeating the same process. My weight flucuated betweeon 130-125 before this time. I have improved and have stopped binge eating. I feel like my metabolism slowed down because of this, are there any ways to speed it up?
Christel Oerum
Congratulations on breaking the binging cycle! That’s an amazing accomplishment. I’d suggest keeping a close eye on what you eat (if you can do that without triggering any unwanted eating patterns) and focusing on a combination of resistance training and cardio. Give it time, and with a structured calorie deficit you will see results
Sally
HI,
I am 16 years old and have been eating clean for more than a year now. However, my weight is not dropping, I am eating foods such as sushi, vegetables, egg, chicken, potato, a small handful of nuts and fruit. I try to minimise my intake of bread and rice for a long time now and have not put a sweet or chocolate or chips or any junk food in my mouth for more than a year now. However slight changes happen and then if I eat one little extra fruit I gain all the weight back and I mean the way I look (really bloated stomach even though i don’t feel bloated). I have been trying for so long to loose weight now and nothing seems to work. I used to go to the gym for one month straight and burned 300-900 calories a day but saw no change. I really don’t know what I am doing wrong. I weigh 75kg and want to be 55kg what can I do?
Christel Oerum
You can eat all the right “clean” food but if you’re not at a calorie deficit you won’t lose weight. My approach would be to track what you eat and your activity for 2-4 weeks and make adjustments based on what you see. If you maintain with your current plan you’ll have to decrease calories or increase your activity. And remember change takes time and consistency
Chlo
Hello I’m 15 and I used to be very overweight and I have lost over 25 kilos over bearly eating for this whole year and lost my period and recently I think iv gained weight over this week when I have bearly eaten everything what should I do
Christel Oerum
So that is obviously not a sustainable or advisable approach. You can lose weight without starving yourself. My approach would be to add in 50-100 calories a week and slowly build up to a sustainable level. That will be scary at first, but your body clearly needs more food. If you can, consider hiring a coach or nutritionist to help guide you.
And you might want to step off the scale. Instant weight loss or gain is not really possible, so if you’re up 1 lb. overnight it will most likely not be fat but rather water or food/waste still in your system.
Chlo
How much weight will I gain and when would I be able to eat normal again
Christel Oerum
If you don’t overeat you shouldn’t gain fat. I highly recommend working with someone who can guide you in a structured way. I can only give general guidance
Morrigan
Hi there, I have a slight problem… I recently realised that I am not eating enough. Today I felt like I ate a lot (with healthy snacks and all) and decided to put every info into a calorie counting app. I had 1400Kcal. In the previous weeks I had even less, sometimes when I checked it didn’t even reach 700Kcal. However, I did not lose weight (or at least not much). I feel lightheaded, dizzy and extremely weak. I don’t do much excercise, I walk for 1-2 hours 3 times a week. Could not eating enough lead to dizziness, even tho I did not lose weight? Should I try eating even more and risk gaining weight?
Christel Oerum
Not eating enough could be what makes you feel extremely weak however it could also be a lot of other things. I’d recommend you start by seeing a doctor to ensure that you don’t have any other underlying issues. Although an extremely low-calorie diet isn’t recommended, if you’re in a calorie deficit you should lose weight. If your doctor gives you the green light you can start slowly increasing your calorie
Daniel Jones
I do 484 calories while at work eating oatmeal, 2 bananas and any vegetables I cook when I leave work I workout at gym burning about 300 to 400 calories a day then I go home and eat more veggies for dinner is that bad to I only do it during the week but I lift weights…so do you think this way is good or bad long-term
Christel Oerum
If you’re telling me that you’re eating less than 500 calories a day, then yes, I think that’s a horrible idea. If you insist on eating that little please reach out to a registered nutritionist so they can help you get the vitamins you need
Jad Ismail
you have a typo. “If you are providing your body with the energy it needs to fuel your ” should be ” if you are not providing”
Tobias Oerum
Thank you for letting us know. We have fixed it now.
Wendy
Hi
I’ve always been a size 8 to 10. Until in my 40s. I did stop eating much because I just can’t face it or not hungry at all. My family make me something at times and say if I don’t eat then they wont. Mostly once a week. But mostly I have two sandwiches of ham or cheese and salad cream no butter and on white bread. But since not eating much and constantly in pain with IBS I have gained weight up to a size 12. Please can anyone help . Its quite frightening.
Thank you wendy
Christel Oerum
If you’re gaining a significant amount of weight and hardly eating I suggest you see your doctor. The lack of appetite and weight gain could be a sign of an underlying issue.
And remember, you also have to consider what else you’re consuming when you look at your daily calorie intake, such as calories drinks and snacks
Kelia
Hello am 15 years old and am very over weight and I have been making my self to starve for the whole day but nothing works I have been doing it for so far 3 months and about exercise I am really very lazy to do them even though I go for jogging just one lap am already tired so what would you advise me I
Christel Oerum
If you’re truly not eating anything (which I wouldn’t recommend for anyone) and not losing weight then you need to see a doctor because then something is off. If you boil it down you need to be in a calorie deficit to lose body fat. So you can reduce your calories or move more. Try tracking everything you eat (including calorie drinks) and see where you’re at. There might be calories sneaking in where you least expect it
Kiera
Hi! I used to have an eating disorder and have been recovering for about a year. However, a few months ago I fell back into the mindset and I began to severely restrict my calories (going from ~2700 cals a day to ~1100 cals a day). This slowed my metabolism down so much! I gained 20 lbs in about 3 months. What would you recommend I do to lose those 20 lbs? I fear that eating more to restore my metabolism will make me gain weight by a caloric surplus, but eating less will only slow my metabolism more and pack more pounds on. Any advice would be appreciated, thanks!
Christel Oerum
In an ideal world, you’d increase your calories slowly and work away from the obsessive food behavior. That is, of course, easier said than done. If you don’t feel like you can do that on your own, one option could be to work with a nutritionist who specializes in diabetes, as well as a psychologist.
As for your weight gain. You shouldn’t gain 20 lbs. if you’re in a calorie deficit. If you gained 20 lbs. in 3 months on 1100 calories, I’d recommend you see a doctor because that sounds like something else might be going on.
Jade
Hey, I’m also in recovery from a eating disorder and lately have fallen in to bad patterns… instead of loosing weight on a low intake of food a day I seem to be gaining… it’s frustrating sense I don’t have any answers to why this is happening. Just wondering if you got to the bottom of the reason you’re body gained weight?
Robert smith
I agree – my advice would be to extend the diet period. Also I’ve found the simplest way to lose weight is substitute lettuce for bread and when you feel peckish, have a prepared bowl of salad in the fridge to snack on. The difficulty I have is breaking the behavioural pattern of reaching out to the fridge every time an irritation or anxiety causing stimulus pushes me in that direction. Also, if making the vingrette for the salad – go easy on the olive oil. Add cider vinegar and a little salt and black pepper and also consider adding a little of your favourite sauce. Salads can be very filling. Especially if you add gently cooked anf cooled diced aubergine along with thinly sliced cucumber.I lost 10kg in 6 months by gently dropping out at least one slice of bread from six slices per day this also reduced the intake of sandwich spread/butter. Slow is best and likely to be more sustainable. Most important try not to eat anything past 7pm on any night.
Wendy Capewell
Hi, I fall into the category of dieting to much and as a result of that I am unable to lose weight. I understand the process etc but I fail understand what you are saying, Are you able to explain it in more simple terms. Thanks
Christel Oerum
Hi Wendy,
I’ll try and simplify Dai’s point.
When you diet for too long and too aggressively it seems that your boy adapts to the calorie deficit and weight loss becomes increasingly hard. We also tend to bounce back and gain a lot of weight when we stop dieting.
What you can do is slowly increase your calories until you get to a higher calorie baseline, keep it there for a while (months preferably) and then diet down slowly from there. I’d also recommend that, if you can, you keep track of your food intake. Many get very surprised at what they actually consume when they do that.
Ursula
I have just completed the 800 Fast, 2 weeks, by Dr Michael Mosely and not only did I not loose anything I actually put on 2 kilos. This is very disheartening. Is it possible I am one of the people who wasn’t eating enough? Help please.
Christel Oerum
That does sound frustrating. 2 weeks is not a long time to diet though, so it might be that you just need to stick with it for a little longer. However, I wouldn’t recommend that low calories without the supervision of a trained professional. The weight gain can’t be fat if you’re in a serious calorie deficit. It could be water or waste.
You could try sticking with it for longer or switch to a more sustainable plan and add in 20-30 minutes of additional activity a day (like walking)
Afiezar
Hi I’m 15 and I have been on a diet for almost 2 months already. So far I’ve lost 10kg in that period of time. I have also been working out on a daily basis. Recently I’ve been adding much more intense work out and I kept the same amount of calorie intake. But somehow I stopped losing weight ever since last week, and your suggestion was to increase my daily intake slowly, starting from two days ago I tried increasing it slowly but it gained me so much kg for some reason. Can you help me out with that?
Christel Oerum
A one week stop in weight loss doesn’t really tell you anything. Weight loss is not linear, you might just have been holding water or not been using the restroom as frequently the last week. So going sticking with your original diet for a little longer probably makes sense.
As for weight gain. There is pretty much no way that you can gain several kilos of fat in that short amount of time. If you’ve upped your carbs or eaten more fibre you’ll be holding more water (not a bad thing, water binds to fibre), and you’ll be carrying around more waste in your intestine.
So don’t panic, and try to focus on body fat percentage and weight loss over time