when does the body use fat for energy?

[raymondh]

most of us do sedentry work, sitting and working on a computer, light walking, driving etc... which does not require many carbs, when does the body use fat for energy? Like wise carbs?

[samv12]

most of us do sedentry work, sitting and working on a computer, light walking, driving etc... which does not require many carbs, when does the body use fat for energy? Like wise carbs?

if am not mistaken the body uses fat when there's glycogen depletion and doing low intensity work. like say for instance when u wake up ur glycogen is depleted from not eating, so if u do low intensity work like walking or slow biking where u don't use muscle u will be burning fat. thats why a lot of people only walk on an inclined treadmill on an empty stomach for fat loss. as far as carbs go, they are the first thing the body burns if available as its the main source of energy so basically u'll be burning carbs all day if u eat them. feel free to correct me or add any info. hope this helped

[DejaBlue55]

You could probably burn some fat by changing your sig.

Haha, but you know I'm just kidding.
But seriously though....

[Superus]

I'm in ketosis as we speak can you believe i use to be a big 188 to now a 144 bitch? lol I'm all about lean gains now i'm trying to start over..

My understanding is you use fat as energy when your carbs are depleted you can lose lots of weight this way.

[Icex999]

raymondh,
Your question should really be 'when does the body use fat as its' main energy source?', because the body is almost always burning a combination of substrates (carbohydrates [via blood sugar], proteins [via amino acids in the bloodstream, either from dietary intake or obtained from muscle tissue in the case of muscle catabolism], or fats [primarily via plasma free-fatty-acids]) rather than just one.

samv12 is correct in that the body favors the usage of fat when you are performing low-intensity exercise (i still recommend that you add high-intensity exercise to your regime because it burns more calories than low-intensity exercise [which will lead to more fat loss since most of the differences in substrate utilizations during any sort of exercise are balanced out in the body post-exercise]), when your blood sugar is constant and relatively low (low liver/muscle glycogen levels also help), or your body is carb-depleted.

Basically, the ideal diet for people with sedentary jobs trying to lose fat is a low-carb diet because this means that during the day (as well as during exercise)the body will utilize more fats due to the lack of carbohydrates in the bloodstream and the rest of the body.

Take a look at this if you care for evidence to back up my suggestions with relation to high-intensity exercise and low-carb diets:

http://www.ncbi.nlm.nih.gov/entrez/q...&dopt=Abstract


I hope that was helpful.

- sheesh

[IronPimper]

raymondh,
Your question should really be 'when does the body use fat as its' main energy source?', because the body is almost always burning a combination of substrates (carbohydrates [via blood sugar], proteins [via amino acids in the bloodstream, either from dietary intake or obtained from muscle tissue in the case of muscle catabolism], or fats [primarily via plasma free-fatty-acids]) rather than just one.

samv12 is correct in that the body favors the usage of fat when you are performing low-intensity exercise (i still recommend that you add high-intensity exercise to your regime because it burns more calories than low-intensity exercise [which will lead to more fat loss since most of the differences in substrate utilizations during any sort of exercise are balanced out in the body post-exercise]), when your blood sugar is constant and relatively low (low liver/muscle glycogen levels also help), or your body is carb-depleted.

Basically, the ideal diet for people with sedentary jobs trying to lose fat is a low-carb diet because this means that during the day (as well as during exercise)the body will utilize more fats due to the lack of carbohydrates in the bloodstream and the rest of the body.

Take a look at this if you care for evidence to back up my suggestions with relation to high-intensity exercise and low-carb diets:

http://www.ncbi.nlm.nih.gov/entrez/q...&dopt=Abstract


I hope that was helpful.

- sheesh

Good info, and to be honest, the body burns fat almost every second of the day. When you sit, sleep, type, lay on the couch, watch tv, etc. Those are all fat burning activities (or non activities as the case may be). Your body will also burn fat when glycogen stores are extremely depleted. For example, first thing in the morning, post resistance training, aduring long term endurance training.

The goal for fat loss is to have the body in a glycogen depleted, but not amino acid deficient state as often as possible. This occurs by managing carbs and doing resistance training. Ideally, when trying to lose fat a person will take advantage of situations where glycogen is depleted by doing medium intensity cardio. For example, when you wake up in the morning, after consuming either bcaa + eaa supplements or a protein only food source you can do 30-45 minutes of cardio at 60-70% of mhr and burn pretty much fat only. Similarly, after resistance training, one can also eat a protein only meal or supplement with bcaa + eaa and do 20-30 minutes of 60-70% mhr cardio and burn only fat.

If we manipulate our carb intake to say, 3 meals per day, we can also take advantage of burning more fat during the rest of our day. Carb meals would include breakfast (after morning cardio) consisting of a low gi carb like oats. This should be the only carb meal until pre workout, which calls for another low-med gi food to make sure that glycogen levels deplete slowly through resistance training. The last carb inclusive meal should be post post workout (following protein only shake and post workout cardio) and can be any sort of carb at a moderate serving. Rice, potatos, oats, whole wheat bread, etc would all be fine for this last carb meal of the day.

If you do these things, keeping protein intake high and overall calories about 1000 below maintenance inclusive of exercise then you should lose 2lbs of fat only during each week. Trying to lose more than this generally does not work in your favor, as the body does not prefer to lose this much fat and would rather use glycogen or protein for fuel. Also remember that the body makes adjustments, and so your cardio, resistance, or diet regimen should be changed every 3 to 4 weeks when cutting to maintain optimal fat loss parameters.