The reason I'm not fat - ketosis?

[Gilded]

I've remained at a fairly constant weight for a very long time even though I'm eating _lots_ of fatty foods (McDonald's, macaroni with cheese... or more like cheese with macaroni, sausage, pizza...) and don't really exercise at all. My calorie intake is sometimes a bit above what it should be and with the amount of fats I'm consuming I probably should be quite overweight by now.

 

My metabolism is rather fast but not extreme and definitely shouldn't overcome my diet and lack of exercise by itself. However, I normally eat a very large meal around 5h before I go to sleep. I tend to sleep quite long (more than 12h sometimes) and don't really like to eat until I've been awake for at least 3h. For example now I haven't eaten anything in the last 20h, and even though there was about 11h of sleep in between I'm wondering if this is enough for my body to go into "starvation ketosis"? If so, how unhealthy this kind of metabolic cycle is?

[Royston]

Not that I can answer your question, but I'm pretty much the same, except the sleeping patterns. I get roughly 4 to 6 hours a night...I have trouble switching off (i.e going over assignment questions in my head et.c.) But my diet can be healthy one week, to binging on fatty foods another week, and there's just no change in my weight. My exercise is rather minimal as well, just running up stairs a few times a day at work, and walking for about half a mile each day.

 

My weight hasn't changed for over 15 years, and it doesn't matter what I do, it just won't shift. I generally have a small lunch, and a large meal about 5 hours before I go to sleep. I know breakfast is important, but I usually just have an apple or a banana, or nothing at all. Whether that has the requirements for ketosis, I've no idea. The simple solution for you, is get a urine test. I personally couldn't care less...I like being thin.

Edited August 16, 2008 by Snail

[Gilded]

Low carb diets base on ketosis (at least the ones that start out with basically zero carbohydrate intake) but I recall it taking normally at least a couple of days before ketosis properly starts. Could be that not eating anything at all results in ketosis in under 24h.

[pioneer]

With the human body the laws of the conservation of energy apply. Energy input minus energy output equals accumulation of body energy or fat. Genetic factors will affect energy output as well as input fuel efficiency. The body can utilize input less than 100% (crap it out). Conscious choices also will have an impact on energy output, such exercise or not. You seem to have a good balance between energy input, fuel efficiency and output so the body holds steady. It is possible obese people are too fuel efficient plus tend to add too much fuel based on energy output.

[Livingstone]

Energy input minus energy output equals accumulation of body energy or fat.

 

Are you hereby suggesting that any unused energy magically transforms itself to fat?

 

I am stumped by nutritionist and people using these two interchangeably, and by the are we refering to fat as in 'body weight' , 'body size' or fat as a dietary element?

 

Its amazing how there is soo much confusion about this!

[Revenged]

biochemical starvation mode starts about eight hours of not eating food...

 

normal metabolism we rely on our glycogen stores in the liver and glucose from digested food replaces them:

 

carbohydrates ingested -> digested to glucose in gut -> absorbed into blood -> utilised as energy or converted to glycogen store

 

biochemical starvation mode starts after about eight hours of not eating food...

 

this is where glycogen stores start to become depleted and are used in metabolism and are not replaced sijnce no food has been eaten...

 

since glycogen stores run out fats (and to a lesser extent protein) are utilised instead...

 

as for ketogenesis i'll explain fat metabolism basics...

 

fat molecule broken down in the liver {triglyceride -> fatty acid + glycerol}

 

fatty acids can be used as energy source but since there is excess fatty acids within the liver and not enough for the muscles the liver converts fatty acids into ketones... ketones can be used as an energy source for the muscles...

 

your metabolic rate decreases with such a long periods (i.e. 12 hours) without food so 'starvation' diets do not work !!! metabolic rate falls so dramatically since humans have evolved over thousands of years to not lose weight during periods of starvation/low food intake...

 

ketogenic diets - e.g. Atkin's diet - is what a lot of people use... this is where restrict the amount of carbohydrates and so you intake so you utilise fat and protein intake... the calories are often the same but you feel fuller... so there is a biochemical basis for this but it is not popular in the medical field as it's most diets advocate low fat and calorie constriction... this is a debate in itself...