Weight Loss

Ever since I started losing weight back in September 2024, I have been posting monthly updates on Instagram. I went from 86 kg to 63 kg (as of October 2025). A lot of you asked me how I did it. So I'm writing this article to agglomerate all points. If you want to skip the story then just read from "The Math" section. Please note that this is not intended to be a scientifically-rigorous article. This is just something I can forward to anyone who asks me how I would go about losing weight if I had to do it once again.


How did I gain weight?

Until 10th grade (March 2017), I was extremely skinny. I weighed around 45 kg as a 178 cm tall teenager. I started my 11th grade at a different place. Given how competitive this stage is in the Indian education system - the stress, the long-hours of sitting, and access to cheap and tasty canteen food caused my weight to balloon all the way to 65 kg by the time I started my degree at IISc in August 2019.

For the first few months of my degree, I think I was more or less stable. In March 2020, the pandemic happened and we all went home, and did not return until January 2022. This period was pretty much staying at home - completing assignments, writing exams, playing video games and binge-watching stuff. By the time I returned to IISc in early 2022, I think I weighed 80-85 kg. By the time I graduated in 2024, I had almost hit 90 kg (my peak weight). At IISc, I had access to nice mess food (probably one of the few college messes in India that's good). I ordered takeout regularly. I snacked a lot. And all of this was accompanied with no physical activity whatsoever - except the occassional cycle ride to classes/lab and walking around the campus. The last semester at IISc was hell. I had to finish my master's thesis, my coursework, apply for jobs and for PhDs abroad.


Previous attempts at losing weight

Sometime in late 2023, I decided to try and lose weight. I started tracking my calories and walking around a lot (10000 steps a day). I stopped eating junk food altogether (this is not a good idea btw). I did all of this for just a couple of weeks. I did not see any results so I stopped.


The trigger

In September 2024, I started my PhD in Germany. I noticed that people around me were considerably fitter. I was slightly reluctant to buy take-out food because it was considerably expensive (I was new to living alone in another country and still had the habit of converting euros to rupees. No way was I paying 700 rupees for mostly tasteless food!). Someone also indirectly fat-shamed/appearance-shamed me. And that was the trigger.


The Math

Your body, like everything else in this universe, is subject to the laws of thermodynamics. If you consume less calories than you burn, then you body has to utilize its calorie reserves to make up for the deficit. It cannot create energy out of nothing (otherwise it would violate the first law of thermodynamics). How is the deficit balanced? By burning fat, glycogen and muscle mass.

One kilogram of fat can store 7700 kcals of energy. So if you have a calorie deficit of 700 a day, you will lose 1 kilogram of fat in 11 days (assuming your body doesn't burn muscle mass or glycogen). In general, if you have an average calorie deficit of \(x \ kcals\) per day, you will burn: \[ \Delta w \ kg/month = \frac{(30 \ days/month) * (x \ kcals/day)}{7700 \ kcals/kg} \] That's it. Create a calorie deficit and you will lose weight. The structured way to go about with this is to estimate your basal metabolic rate using a calculator like this and account for additional calorie expenditure on the basis of your current activity levels. If you aspire to lose 1 kilogram a month, you should maintain a calorie deficit of 250-300 kcals per day on average. You may choose to estimate your calorie intake, or you can be precise by using a weighing machine (for food) and looking at nutrition labels.


Nuances

In the very beginning, your body may lose weight faster because it is burning glycogen. Every gram of glycogen is bonded to 3-4 grams of water. Your body may have around 500 grams of glycogen stored at anytime, which is accompanied by a water weight of 1.5 to 2 kg. However, this glycogen store may get quickly replenished when you eat a lot of carbs - which again comes with a lot of water weight. Eating excess salts may also cause water retention. These are the important factors which make your weight fluctuate along the time-scale of days - but your aim is to lose fat. This is why it is important to track your weight daily (ideally in the morning, after using the washroom but before consuming anything) but only look at weekly averages in order to estimate actual weight loss due to fat loss.

Another important nuance is loss of muscle mass. The higher muscle mass you have, the higher your basal metabolic rate is, and the easier it is to lose weight. However, losing some muscle mass is unavoidable while you are in calorie deficit across several weeks. You can minimize this loss by eating a lot of protein. As a rule of thunb, eat 2 grams of protein for every kilogram of your body weight. You can do strength training at the gym to maintain your strength and muscle mass. You can minimize loss of muscle by maintaing low calorie deficits. A deficit of 250-500 kcals per day accompanied with adequate protein intake and some strength training is ideal.


WTH are these weight-loss diets and regimes?

Any weight-loss diet or regime is a means to introduce a calorie deficit. You may not have to follow any of them. Just maintain a calorie deficit and you will lose weight. For purpose of completeness, I have summarized some of them below:


I can't lose weight?!

There are two ways to introduce a calorie deficit - decreasing calorie intake or increasing calorie expenditure.

You can be more precise about the former by accurately measuring your calorie intake using a weighing machine. Some tips to reduce calorie intake:

  1. Eat foods that induce satiety - essentially foods that are high in fiber
  2. Limit sugary drinks, sweets and fried food. They are all high in calories. They are not nutritious. They do not make you feel full
  3. Avoid alcohol. It lowers your body's metabolism
  4. Have meals at proper times in order to limit irreguarly-timed hunger which may promote snacking
It is much more difficult to accurately estimate calorie expenditure. You may still choose to increase it. The go-to approaches are to do cardio at the gym, walk a lot, run/jog, bike, swim, etc.

There are some factors which may make it difficult for people to lose weight - because they have a low basal metabolic rate to begin with. As far as I know, these factors are:
  1. Being female: associated with lower metabolic rate due to lower muscle mass
  2. Being short: a tall person requires more calorie expenditure to move their body around
  3. Being old: younger people just have higher metabolism
  4. Weighing less: this may sound ironic - why would a person with less weight need to lose weight? Let me explain - suppose there are two people who are classified as overweight/obese (according to BMI or body fat percentage) - a short person weighing 60 kg and a taller person weighing 90 kg. The taller, heavier person just has a higher metabolic rate because their body burns more calories in order to move them around.
  5. Having certain metabolic disorders: thyroid issues, PCOS, etc
Factors 1-4 are evident from basal metabolic calculators. If you are suffering from a myriad of these factors then weight loss may be harder for you. If you are extremely over-weight or obese, then your doctors may (as of 2025) prescribe weight-loss medications (like GLPs) or bariatric surgery.


Potential Issues

You may face some side-effects of weight loss. Personally, I had some hair-fall after the initial months that I attributed to telogen effluvium. There may also be some loose skin. This can be minimized by losing weight slowly and by doing strength training to fill up the underlying volume with muscle. Whether loose skin may retract or not seems to be dependent on age, genetics and location of the loose skin. It may take a lot of time. Losing too much weight and becoming underweight is not a good idea. During your weight loss period, make sure to have a balanced diet full of macro-nutrients and micro-nutrients.


Where am I right now?

I currently weigh 63 kg. I keep track of my calorie intake daily. I use the food weighing machine to be more precise. I eat around 2500 kcals a day. I do not deny myself of junk food. I just try to limit the amount. Nowadays, I have been losing just 500-600 grams a month. I am trying to decrease my body fat percentage further, and increase my muscle mass. I aim to eat 120 grams of protein a day. I do strength training at the gym 3 times a week. I go rock climbing 1-2 times a week. I play badminton for 1.5 hours once a week. I bike to work (~1.5 km). Summer is over so I cannot bike long-distance easily. I tried running/jogging but I do not like it. I measure my weight daily and track weekly averages.


Concluding remarks

Wishing you good luck! Losing weight just requires some discipline and patience. Keep record of your journey in order to fuel your motivation. It would be nice if you have supportive and motivational friends like I do. Lastly you can always look at your before-and-after pictures to see how far you have come.