Guest guest Posted July 30, 2005 Report Share Posted July 30, 2005 Jo- >OK, what is leptin and why should it be " mastered " ? I'll repost my earlier message on the subject for you. Basically, your fat cells secrete leptin, which is a hormone that has a lot of functions in your body. One of them is to tell your brain how much fat is on hand: all else being equal, the more fat you have, the more leptin you produce. This is one of the key signals that your brain (specifically your hypothalamus) checks in order to decide what to do with your metabolism (rev it, shut it down, etc.) and how to set your appestat. Unfortunately, it's easy to become leptin-resistant. Just as eating too much sugar and other carbs eventually causes your body to become partially " deaf " to insulin, releasing too much leptin can cause your body to become resistant to it too. And since insulin stimulates the release of leptin, the two conditions are tightly related. Worse yet, since MSG damages the hypothalamus, you can actually take a short-cut to becoming leptin-resistant. (This is almost certainly at least one reason MSG consumption causes obesity in many people.) As you can conclude from the insulin-leptin relationship, leptin levels aren't supposed to be the same throughout the day. In fact, your body is supposed to have a sort of rhythm, with peaks and gentle slopes, and that rhythm is tied into an enormous variety of other systems in your body. It wouldn't be particularly ridiculous to think of leptin as one of several " master " hormones, in fact, which is why insulin and leptin problems have so many complications even if the connections aren't always obvious. (Leptin is involved in the release of growth hormone, for example, which is one of the most important hormones in your body.) This is one of the reasons that snacking is such a bad idea. Snacking keeps hitting your body over the head, so to speak, with insulin and then with leptin, keeping levels unhealthily high and pushing the whole delicate system out of whack. Hence the rule offered in _Mastering Leptin_ that you should always make sure to go a minimum of 5-6 hours between meals, with no exceptions, and at least 11-12 hours between dinner and breakfast, in order to restore and maintain the correct leptin rhythm. Sleep, particularly in the later hours, is prime fat-burning time, but eating too soon before bed postpones and even prevents this and also messes up the release of growth hormone, which is why you need an appreciable amount of time between dinner and bed -- the larger the meal, the longer the time. If you're getting hungry before bed or during the night, or if you're having trouble sleeping because of any kind of food issues, it's a strong signal that your whole system is disturbed and needs serious adjustment. Where s goes wrong in _Mastering Leptin_ is in his treatment of carbs and dietary saturated fat (which he foolishly says is healthy but should be kept to a relative minimum) but that's food for another post. I highly recommend the book despite some serious caveats, though, because there's no other resource I know of which so thoroughly elucidates the tangled web of bodily systems leptin is involved in, even though there's vast work on the subject yet to be done. For the sake of comparison, here's what Rosedale says on the subject of carbs. >>I have been asked to summarize in a single sentence what would best >>promote health. It is this: Health and lifespan is determined by the >>proportion of fat versus sugar people burn throughout their lifetime. The >>more fat that one burns as fuel, the healthier the person will be, and >>the more likely they will live a long time. The more sugar a person >>burns, the more disease ridden and the shorter a lifespan a person is >>likely to have. and >>However, most people become very adapted at burning sugar; your body >>continues to want to " keep playing " sugar, to burn more sugar, even when >>you are not eating. When you're sleeping at night, your body then prefers >>to burn sugar and it gets that sugar by breaking down proteins in your >>body, which means lean body mass, which includes muscle and bone. I call >>that metabolic momentum. >> >>Your body continues to like to do what it has become accustomed to doing. >>If you have burned sugar throughout the day, you prefer to burn sugar at >>night even when you are not eating. Your body does not store very much >>sugar and prefers to hold onto much of it and, therefore, you'll continue >>to manufacture sugar by a process called gluconeogenesis from lean body >>mass. You store fat -- and, in many people, lots of it -- in your >> " cupboard " and not very much sugar, because fat is the fuel that your >>body would prefer to store and later to burn to stay healthy. >> >>However, when you eat sugar and fat together, your body will burn sugar >>first. I believe that it burns the sugar off because that is one way to >>get rid of it. Sugar causes damage by glycosylation and having it around >>too long is extremely damaging and accelerates aging. This is ironic, since his dietary recommendations are fairly serious out of step with his own conclusions. In fact, I can't recommend one of his articles on Mercola's site highly enough. http://www.mercola.com/2005/jul/7/muscle_fuel.htm Here's the opening: >>Some of you may be thinking, " I may eat a lot of starchy carbohydrates, >>but at the same meal, I am also eating protein and fat. Why am I just >>burning sugar and storing fat? " It's a good question, and it gets to the >>heart of the vicious cycle. >> >>Let's assume that you are following the current dietary recommendations >>that tell you to eat more than half of your daily calories in the form of >>carbohydrate. You fill your plate with a cup or so of pasta, topped with >>meatballs, some tomato sauce and cheese. >> >> From the minute the pasta is in your mouth, it begins to be broken down >> into simple sugar. Your body can only store a small amount of sugar at a >> time in the form of glycogen that is stored in muscle and liver. What's >> not stored as glycogen is burned off as quickly as possible, forcing you >> to burn sugar, but your cells can only burn so much off at a time. >> >>What happens to the rest of the sugar that isn't being stored or burned? >>It is converted into saturated fat. What about the protein and the fat in >>the meal that you just ate? Some of the protein is taken up by the cells >>for repair and maintenance, but your cells can only utilize a small >>amount of protein at a time. The rest, largely, is turned to sugar and >>stored as saturated fat. That leaves just the fat that is not burned when >>sugar is around to burn, which gets stored away as more fat. >> >>Why isn't the protein and fat burned as fuel? Because you must first burn >>up sugar if it is available. If you eat sugar and fat together, you have >>to burn sugar first before you burn the fat. Furthermore, your cells get >>used to burning a particular fuel, in this case, sugar. >> >>When you are younger, your metabolism is more flexible, and you can >>switch fuels more easily. As you get older, your cells get stuck in a >>rut, and if they are used to burning sugar, they will look for more sugar >>to burn when they need fuel. I haven't read Rosedale's book, but s suggests keeping dietary saturated fat down if you're overweight because you want your body to burn its stored fat rather than relying on food instead. From my research and experience, though, that's a grave mistake. Your body burns what it's trained to burn, what it's used to burning. So eating saturated fat and minimizing sugar (which includes starch, since it's broken down into sugar) is in fact a terrific way to train your body to burn saturated fat! (This raises an interesting question about whether coconut oil and other unusual MCT sources are really so great in the long run, but this time I mean it -- food for another post.) I'd also like to point out that metabolism of fat is a comparatively clean process while metabolism of sugar produces more oxidative stress, free radicals and general systemic damage. Furthermore, much of what we know as aging is simply glycation -- the cross-linking of proteins by sugar. IOW, if you want to stay as youthful and healthy as possible, it behooves you to AVOID sources of sugar, train your body to burn fat, and of course avoid unnecessary unsaturated fatty acids, not to mention consume plenty of antioxidants and other compounds which prevent and even reverse glycation and lipid peroxidation. (Obviously this is in addition to all the usual admonishments about eating nutrient-dense foods, getting enough of the right kinds of exercise, etc. etc. etc.) Hope this helped. - Quote Link to comment Share on other sites More sharing options...
Guest guest Posted July 30, 2005 Report Share Posted July 30, 2005 --- In , Idol <Idol@c...> wrote: > I'll repost my earlier message on the subject for you. Thanks , this is great info. <snip> > Unfortunately, it's easy to become leptin-resistant. Just as eating >too much sugar and other carbs eventually causes your body to become >partially " deaf " to insulin, releasing too much leptin can cause >your body to become resistant to it too. And since insulin >stimulates the release of leptin, the two conditions are tightly >related. Here's a mental leap - if someone was massively overweight, then severely restricted carbs for a couple of years, could that screw up leptin production? DH lost 140lbs on a very low carb diet, then gained it all back while following the same diet. He has since gained yet more weight, and is over 200lbs overweight. Something is not right with him, and I just have no idea what. If his blood sugar dropped too low, and hence insulin too low, leptin could be too low, right? (Although he didn't show any signs of BS dropping too low though) Interestingly, he leaves long periods between eating. Often he eats once per day or less. Probably less than 1500 cals daily. Then one day he'll be starving and eat loads, or if we go on holiday he always eats very well. Thanks again Jo Quote Link to comment Share on other sites More sharing options...
Guest guest Posted July 30, 2005 Report Share Posted July 30, 2005 Jo- >Here's a mental leap - if someone was massively overweight, then >severely restricted carbs for a couple of years, could that screw up >leptin production? Not according to anything I know. >DH lost 140lbs on a very low carb diet, then >gained it all back while following the same diet. He has since >gained yet more weight, and is over 200lbs overweight. Something is >not right with him, and I just have no idea what. If his blood sugar >dropped too low, and hence insulin too low, leptin could be too low, >right? (Although he didn't show any signs of BS dropping too low >though) > >Interestingly, he leaves long periods between eating. Often he eats >once per day or less. Probably less than 1500 cals daily. Then one >day he'll be starving and eat loads, or if we go on holiday he always >eats very well. How tall is he? 1500 calories per day sounds awfully low for a man. Blood sugar plunges are generally caused by insulin spikes, which move lots of sugar into cells to be stored or used, and insulin overproduction and leptin overproduction go hand in hand, though they're not literally in sync throughout the day. I'd need a lot more information to make any real suggestions for your husband, but if you're interested, send it my way and I'll offer what I can, either onlist or off, at your discretion. - Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You are posting as a guest. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.