HELP! Is my metabolism messed up?

CherylG1983

I had the same problem. Actually, pretty much the exact same! I'm also 5'10, but I went from 180 to 216 in about six months and I couldn't figure out why. So, I cut out wheat completely. Not because of gluten, but because it raises blood sugar and causes insulin spikes. When I did, within a few days it was like someone popped a balloon in my belly! I stayed off wheat, and I've lost 15 pounds in 2 months. This is along with a healthy diet and exercise, of course. I also seriously limit my dairy intake. I just have the occasional greek yogurt and maybe a 1/4 cup of skim milk mozzarella cheese a week. I feel great, and I'm so impressed with the results I've achieved after so long of not being able to lose a single pound!

Leonidas_meets_Spartacus

I eat 80% fat, 15% protein and 5% carbs. If protein/muscle was preferred source of fuel for my body, I would have lost lot of muscle. Yet sitting on a couch I burn 200 g of fat every day, not muscle even on days with calorie deficit. Don't believe what you read on the internet blogs. Its very consistent with the university I work with, and not something where you see body burning all the muscle.

I don't think you're understanding the underlying processes correctly. Why do you think you would have lost a lot of muscle based on your dietary intake of 80% fat, 15% protein and 5% carbs? If you were eating at maintenance or surplus, there would be no reason for your body to break down muscle. If you were eating at a caloric deficit, it may happen (but can be preserved or minimized with adequate protein intake and heavy resistance training).

Nope, the body doesn't work that way when it comes to fuel. I will dumb down the science for you if you don't have a bio chemistry or medical background. The body breaks down ATP from either glycogen/Fat or protein/lactic acid. The liver (glycogen supplies 2 ATP, fat supplies 34 ATP and the lactic acid comes last last usually at higher intensities. The problem most people face is they do high intensity exercises where the lactic acid is primary fuel because there aren't eating enough and fat can't keep up with the energy requirement. If your body is fat adapted, it can supply the energy just fine till you increase the intensity. IYes people lose muscle but thats because they eat too little and don't work out at the right levels. Human body can adapt just fine and for thousands of years did just fine when people would go with out food for a period of time. I am done here but unless you have a medical degree or know bio chemistry stop spreading rumors or fake science.

There was a scientific experiment done on a Man who starved for weeks and how the body reacted, its widely quoted study on how the liver reacts and what fuel the body uses.

Actually, I do have a degree -- in biology from UC Berkeley, so I understand the science fairly well. But, thanks.

Once again, not sure where your conflict is here. So, far I agree with what you're saying for the most part, but your understanding of the role of lactic acid, protein and fat in cellular respiration is incorrect.

Lactic acid is a byproduct of anaerobic cellular respiration -- when there is not enough oxygen present for the higher yield aerobic respiration seen in the Krebs cycle. It only consists of the first step of glycolysis where glucose is broken down into pyruvic acid along with two ATP and the pyruvic acid yields lactic acid after a reaction with NADH. This is why lactic acid builds up in muscles during high intensity exercise -- because the body cannot provide the cells enough oxygen for continued energy release of the Krebs cycle of aerobic respiration (which provides far more ATP -- 34 or so) -- and why you will eventually cramp and will not be able to continue high intensity exercise for long periods. The better your cardiovascular capacity, the more efficient you will be in delivering oxygen to the cells and can exercise for longer at high intensity levels.

Glucose is the start of both of those processes, not fat nor protein (and certainly not lactic acid which is an end byproduct!). However, where that glucose comes from can be a variety of sources -- already present in the blood stream from carbs, glycogen stores primarily in liver and skeletal muscle, protein (from muscle) and fat (from both muscle and adipose tissue). The body will access blood glucose first, then glycogen stores. Once those are depleted, the body needs to look to both muscle and body fat for extra energy (primarily the liver converts both into glucose through the process of gluconeogenesis, which is the synthesis of glucose from non-carbohydrate sources -- i.e. protein and fat). And depending on the circumstances, the body will look to one or the other -- but often a combination of both. The key to better fat loss is minimizing the muscle used as fuel for glucose part of the equation.

So, when you attempt to talk down to someone about something, make sure you get your facts straight.

This is also why higher volume lower intensity exercise will burn a higher percentage of fat vs. muscle. It will not burn as many total calories as high intensity exercise for the same duration, but a higher percentage of the calories it does burn will be fat versus muscle because the body is able to keep up with the oxygen demands in lower intensity exercise (walk, hiking rather than sprints) and break down more fat for energy rather than muscle (after your glycogen stores have been depleted).

So, once again, I agree with you on most of your comments and don't see how any of this contradicts in any way the fact that 1 lb of fat releases 3500 kcals whereas 1 lb of muscle releases much fewer kcals (some say 600, some say closer to 1500). Or the fact that when you're in a caloric deficit, you generally lose both fat and muscle. And one of the ways to minimize or eliminate (though true elimination is difficult) is by significant resistance training and sufficient protein intake.

Once again, where is your conflict?

I would ask for a refund if they taught you that Glycogen produces more ATP molecules than Fatty acid oxidation(34 ATP molecules) at aerobic levels.

I have a conflict when some one says, just because your are losing higher amount of weight, you lose muscle. Yes it will eventually depending on the other factors. However, its not entirely true, even when you are starving, the liver is going to start making ketones. Which is why people can survive with out eating, not because the body is eating their muscles. Also at higher intensity, the fat burning is very less. Once you hit anaerobic threshold or close to it or say 80-85% Vo2 max, your body will use upwards of 95% glycogen. Its pretty easy, put a mask, measure O2 and CO2, at higher intensity and get the RER or RQ.

I just ran a Half marathon yesterday, finished 3rd with just water and didn't carb load nor took any gel shots. If what you are saying was true, with less than 50 carbs/day for last few months, my body muscle would have melted instead of fat. For a fat adapted metabolism, the glucose use will come much later during a workout. When I am sitting on a couch or till I hit Hr of 155 my RER/Respiratory quotient is between 0.72-0.77, which means I am burning predominately fat. Now, if you consider a Sprinter or a guy who runs 100-800m, their bodies are straight up tuned to consume glycogen from the start.


Human body is very flexible and complex and knows how to survive before eating all the muscle. I have seen people wrecking their metabolism by eating little and doing high intensity work outs. They end up with flab but not because body wants to eat muscle first. If that was the case, I would be like a skeleton with out any muscles.

lindsey1979

I would ask for a refund if they taught you that Glycogen produces more ATP molecules than Fatty acid oxidation(34 ATP molecules) at aerobic levels.

You don't understand what you're talking about. Glucose is the basis for both processes. The first step is called glycolysis -- it is the hydrolysis of glucose, yielding pyruvic acid. If oxygen is present, pyruvic acid is ultimately oxidized yielding 34 ATP in the process -- it's known as the Krebs cycle of aerobic cellular respiration coupled with oxidative phosphorylation (via the electron transport chain). Fatty acid oxidation comes in when you're dealing with ketones to break them down to Acetyl-CoA to enter the Krebs cycle for aerobic respiration. If oxygen is not present, such processes are not possible and pyruvic acid is converted into lactic acid through a reaction with NDAH+. So the only ATP yield there is the initial net 2 ATP in glycolysis. This is anerobic respiration or also called lactic acid fermetation (as you see it in certain bacteria as well).

In BOTH situations, the starting point is GLUCOSE (unless you're talking about ketones -- see comments below). Glycogen is a storage form of glucose (it's a polysaccharide made up of several units of glucose) --- it's very easy for the body to break down glycogen into glucose, which is why it's usually the second source of glucose used after that which is already present in the blood from dietary carbs.

You learn this in basic biology -- any intro college course will have it. Shoot, if you take AP biology in high school, you'll learn about it in high school.

I have a conflict when some one says, just because your are losing higher amount of weight, you lose muscle. Yes it will eventually depending on the other factors. However, its not entirely true, even when you are starving, the liver is going to start making ketones. Which is why people can survive with out eating, not because the body is eating their muscles. Also at higher intensity, the fat burning is very less. Once you hit anaerobic threshold or close to it or say 80-85% Vo2 max, your body will use upwards of 95% glycogen. Its pretty easy, put a mask, measure O2 and CO2, at higher intensity and get the RER or RQ.

I just ran a Half marathon yesterday, finished 3rd with just water and didn't carb load nor took any gel shots. If what you are saying was true, with less than 50 carbs/day for last few months, my body muscle would have melted instead of fat. For a fat adapted metabolism, the glucose use will come much later during a workout. When I am sitting on a couch or till I hit Hr of 155 my RER/Respiratory quotient is between 0.72-0.77, which means I am burning predominately fat. Now, if you consider a Sprinter or a guy who runs 100-800m, their bodies are straight up tuned to consume glycogen from the start.

Yes, the body can largely run on ketones as well as glucose; however, certain processes REQUIRE glucose. Luckily, the liver can produce enough through gluconeogenesis if no dietary carbs are present (i.e. turn protein or fat into glucose). You see this with folks that eat virtually no carbs like the Inuits, who also have larger than average livers they believe to accommodate this need. When glucose is present, it is the preferred fuel source. To get your body to use ketones as fuel, you have to restrict carb intake -- this is the basis for ketogenic diets. However, even for those that are in ketosis and a calorie deficit, they generally also lose muscle as well as fat.

There is a debate as to whether it's the low carbs and ketones that get that result or if it's the protein intake that is the determinative factor as I've seen studies on both -- studies that show similar LBM loss reduction both in ketogenic diets and non-ketogenic diets with similar protein amounts. In fact, I've only seen one study where LBM was not lost at all when in a caloric deficit and that involved elite athletes. If you know of any other studies that show that, please share. I haven't seen any studies that showed a ketogenic diet = no LBM loss in a caloric deficit. I'd love to see such a study. But, as of yet, I've never read a study that showed that.

If the body is starving, it will definitely "eat" both muscle than fat. Look at the famous Minnesota study. I can't believe you really think that even if you're starving that your body is not catabolizing muscle (as well as fat). If I'm interpreting your statement correctly, then you really don't know what you're talking about.

Human body is very flexible and complex and knows how to survive before eating all the muscle. I have seen people wrecking their metabolism by eating little and doing high intensity work outs. They end up with flab but not because body wants to eat muscle first. If that was the case, I would be like a skeleton with out any muscles.

I'm not saying that the body eats all the muscle, but only than when in a caloric deficit, people generally catabolize BOTH muscle and adipose tissue. And, the way to shift the balance so you catabolize less muscle and more fat is to (1) resistance train significantly (i.e. lift heavy) and (2) get sufficient protein in your diet.

Whether you choose to do a ketogenic diet or one with carbs with sufficient protein seems to be more an area of preference as research has been shown in both studies to minimize LBM loss. So, the thought is that it's not the carbs that's the determining factor (i.e. glucose vs ketones as fuel) but sufficient protein intake. However, I'm sure there is still plenty more research to be done here on how this really works as the research is still in its infancy.

expressre

If your really concerned its probably a good idea to go to the doctor and get yourself checked out. I recently had some problems that I thought could be related to weight loss so I brought it to my docs attention and had some blood work done. It turns out everything was fine but my Vitamin D levels. Vitamin D Deficiency can attribute to weigh gain from some of the research I did.

http://www.caloriewarrior.com/my-blood-work-protein-levels/

http://www.caloriewarrior.com/vitamin-d-deficiency/