Keto deit. No weight loss in a defecit.

[Michael_Hay]

Ok here are the stats. 

-Male

-200 lbs 

-keto 5% carbs. 25%  protein 70% fat. 

-Resting metabolic rate of 2550

-according to  Fitbit, I burn 3500-4200  calories per day. 

-Age 34 

-Cardio 5 days per week 40% of the time in -peak. For 30 minutes. 

-Weights 3 times per week 60 minutes. 

-Ride my bike 2  hours per day. 

 Sleep 8  hours each night. 

1) When I   started i was in a huge calorie shortfall.  Eating only 1800 calories per day. Mental energy was great but i was physically drained. I kept this up for 3 weeks. I lost only 1 lb! Can anyone explain this? 

2) Now i have been eating maintenance calories have lost 2 lbs this week. Actually one day this week ate 4000 calories a lost.5 lbs the day after. 

  I'm confused. It seems my body needs either maintenance calories or a   surplus to lose weight. Is this because of the amount of exercise I do? Does anyone have any feedback for me? 

[Dominique]

Welcome to the community, @Michael_Hay, and thanks for providing detailed information! How tall are you? The reason I’m asking is 2550 calories sounds very high for RMR. Likewise, total calories burned are also likely on the high side (which is not uncommon when using an activity tracker to estimate them), even though your average step count (currently 17.3k as per your profile) does point to your being more active than most.

You may want to use this online calculator in order to get a "second opinion" about calories burned. Assuming you’re 6’ 0" tall and a "high" activity level, BMR would be 1885 and TDEE 3252. If you are shorter, the numbers would be correspondingly lower.

As to your diet, keto is not necessarily the optimal choice for someone chosing to be very active, as carbs are the body’s preferred/default fuel for activity. If you decided to settle for that approach regardless, you should allow enough time to become "keto adapted", i.e. have your body get used to relying on fats rather than carbs as its source of energy. From a weight loss perspective, your style of eating doesn’t matter, however: it’s all about being in a caloric deficit.

The problem when changing all parameters (diet, activity, lifestyle) at once is it’s difficult to pinpoint what is causing things not to work as expected (e.g. with weight loss). Make sure whatever you are doing (e.g. in terms of eating and activity) is sustainable over the long term. Even though Fitbit is likely overestimating your energy expenditure, you should be able to eat more than 1800 calories and yet lose weight.