My problem is that when I start losing weight I feel so exausted that:

  1. I'm angry
  2. I'm dumb and cannot do any mental work
  3. I always want to cheat my diet in the end of the day

All those ads say that I should be energized as a rocket and be happy with my results. But how can this happen if losing weight is not my body natural state?


  1. I am exercising 3 days cardio (3.75 miles running) + 3 days of weight training with personal trainer (1 hr). This is an ideal week - I usually miss 1 day of cardio.
  2. Yes, I'm dieting. I think my error is that I do not count calories. Still on my TODO list. I do eat self prepared food however
  3. I lost 15 pounds during 2 months and now it stopped going down with no obvious changes to lifestyle.

  4. I work as a software project manager, so yes - it's a desk job. And I do not feel pretty good during the day when I do not eat enough.

So yes - my question can be rephrased the way Tony says - "Should losing weight make me feel exhausted?"

Sorry for my English just in case :).

  • sounds like you aren't eating enough. i get grumpy when i am hungry.
    – KJYe.Name
    Apr 12, 2011 at 18:48
  • Yeah I think so too. But isn't loosing weight all about calories deficit? So my fat will get burned.
    – Nikolay R
    Apr 12, 2011 at 18:54
  • not completely true. try eating healthy food in small multiple portions.
    – KJYe.Name
    Apr 12, 2011 at 19:36
  • 1
    Could you please be more specific? - Are you exercising? If so, how much per week? - Are you dieting? If so, how many calories are you cutting per day or per week? - Are you actually losing weight? Please indicate gains or losses? - What does "mental work" mean? i.e. Do you have a desk job and are having difficulty doing your work? Or perhaps I misunderstood the question. Is it something like, should losing weight make me feel exhausted? or maybe, why don't I feel better after losing weight?
    – Tony R
    Apr 12, 2011 at 20:26
  • 1
    Yes it is about a calorie deficit, but not so low your body doesn't function normally any more.
    – Ivo Flipse
    Apr 12, 2011 at 23:15

2 Answers 2


I'd take a look at what you are eating in addition to how much you are eating. A diet consists of many facets, and you are trying to do something that is not natural for your body to do: lose weight. The challenge is to trick your body into burning its fat instead of just the food you consume. The problem is that many times people cut too much of the wrong things and are actually becoming counter productive.

My personal weight loss journey started with an unbalanced diet. The key to the diet was controlling the pancreatic function. There's a number of diets that are similar in nature to what I did, but there's a few principles to glean even if you choose to keep a balanced diet.

  • If you don't eat enough protein you will lose muscle.
  • Muscle burns fat.
  • Fat contains 3500 calories, and muscle contains 600 calories. In blood glucose shortages, you will burn both of these together--guess which shrinks faster?
  • Exercise on too few calories and not enough protein accelerates the loss of muscle. Not what you'd expect?

Now, you might need a higher protein than normal while you are losing weight and exercising. So your extra calories have to come from somewhere else.

An ubalanced diet such as Atkins, South Beach, or Ideal Protein (the one I used) are designed to be temporary. In short, you lose the weight, and "phase off" the diet to maintain--which is something your body is really good at doing. They put the body in a state called "ketosis", which is fine for 3-4 month stretches. Essentially, you have very little carbs (less than 40g a day) and your pancreas will switch over to secreting glucogon which is designed to burn fat and convert it to blood glucose. In essence your body is still getting its full supply of calories needed based on your BMR, but the balance is coming from your fat stores. However, if you don't have enough protein on one of these diets you will start burning muscle along with the fat which is not what you want.

The irony is that simple calorie deficits don't solve the problem you want. Low blood sugar makes you very mean and makes it hard to think. Another, often overlooked problem that has the same effect is dehydration. You need to be drinking lots of water throughout the day. It helps with the weight loss, and it helps with the mental clarity.

Certain parts of your diet have minimum requirements, and going below the minimum needed to satisfy a calorie deficit will do more harm than good:

If you eat about four times a day (breakfast, lunch, dinner, snack) or more, it will help you get through the day with a more even temperament. I also recommend getting more calories from vegetables outside your protein source than grains or anything like that.

  • Do you have a source for this: "Fat contains 3500 calories, and muscle contains 600 calories." Also, do you have evidence that the body burns fat and protein equally in blood sugar deficit. My textbook says the body will burn fat as its main source until the fat supplies run low.
    – Kenshin
    Jan 21, 2013 at 23:43

You were not too exact, so my assumptions: Seems like you have tried at least more than once, and have quit due to these three factors each time. The thing is: it takes some time and effort before the results kick in, not only in terms of weight or looks, but also for your energy levels and general happiness.

Next: are you having enough fun while exercising/playing? Most of the time, people who enjoy their fitness activity also enjoy the rest of the day, like fitness being a hobby or a second job, or, for some people a religion.

Try getting more rest and stay motivated with your physical activity. A lot of resources and people can tell you how you can get some variation and do things the fun way.

Drinking lots of water will let you stay in a better mental and physical state, and will (though this is only in my case) let you think more too!

The BIGGEST thing is that fitness is like any other investment: results and a general feeling of well being only show up after you have put in some (by 'some' I mean considerable) time and effort. The initial few days are always tough, not only during the exercise' but the rest of the day too.

  • Karunesh, you are correct. I did not quit now yet, but I do not enjoy my physical condition right now. I do have fun time during weigth training, not during cardio. ) Maybe the problem is that I do not sleep enough. Hard to do though )
    – Nikolay R
    Apr 13, 2011 at 14:34

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