by "teaser"
Wed, Mar-24-10, 21:54
There is also strong indication that being resistant to the hormone leptin, which results in Jimmy’s basic condition of having a low body temperature, insulin resistance, and weight problems – is exacerbated by a low-carb diet, especially when that low-carb diet is high in omega 6 polyunsaturated fat, which most low-carb diets are...
Leptin decreases the preference for carbohydrate. They've shown this again and again. It increases lipolysis, the free fatty acids spare glucose in some cells by competing with glucose for oxidation, the ketones spare glucose in other places. The major purpose of leptin seems to be to allow the body to survive in fasting condition, which is basically low carb. It's built right into the system. If you want to see leptin resistance, eat lots of carbs. Your leptin goes up, while free fatty acids and ketones go down. That's leptin resistance. Lots of leptin, not doing much. I've become very skeptical of leptin refeeds.
If a person didn't eat a lot of carbs, but was still leptin resistant, I would guess at the same basic cause; no shortage of glucose. This time, produced in-house.
I was looking at a Kekwick and Pawan study today.
Of particular interest is the effect of a 1000 kcal diet providing 90 percent of the calories as fat on the metabolic pattern of obese patients.
Non-obese subjects, after a few days on this diet, develop marked ketonaemia, ketonuria, hypoglycaemia and negative nitrogen balance; the obese exhibit little or no ketosis, maintain blood-sugar and plasma bicarbonate values within normal limits, show little protein loss (as judged by nitrogen balance), and appear to tolerate the diet without undue discomfort for at least a few weeks
Free fatty acids can't be stored as triglyceride in fat cells without glucose. If glucose needs sparing, maybe the body will "waste" fat to provide ketones, as well as glycerol for gluconeogenesis?
Maybe omega 6 messes all this up. That's entirely beside the point. (Omega 3 raises leptin. I'm not sure whether this is a good thing, anymore.)
Matt should leave Jimmy the heck alone. Sorry for the strong language. :nono:
Leptin decreases the preference for carbohydrate. They've shown this again and again. It increases lipolysis, the free fatty acids spare glucose in some cells by competing with glucose for oxidation, the ketones spare glucose in other places. The major purpose of leptin seems to be to allow the body to survive in fasting condition, which is basically low carb. It's built right into the system. If you want to see leptin resistance, eat lots of carbs. Your leptin goes up, while free fatty acids and ketones go down. That's leptin resistance. Lots of leptin, not doing much. I've become very skeptical of leptin refeeds.
If a person didn't eat a lot of carbs, but was still leptin resistant, I would guess at the same basic cause; no shortage of glucose. This time, produced in-house.
I was looking at a Kekwick and Pawan study today.
Of particular interest is the effect of a 1000 kcal diet providing 90 percent of the calories as fat on the metabolic pattern of obese patients.
Non-obese subjects, after a few days on this diet, develop marked ketonaemia, ketonuria, hypoglycaemia and negative nitrogen balance; the obese exhibit little or no ketosis, maintain blood-sugar and plasma bicarbonate values within normal limits, show little protein loss (as judged by nitrogen balance), and appear to tolerate the diet without undue discomfort for at least a few weeks
Free fatty acids can't be stored as triglyceride in fat cells without glucose. If glucose needs sparing, maybe the body will "waste" fat to provide ketones, as well as glycerol for gluconeogenesis?
Maybe omega 6 messes all this up. That's entirely beside the point. (Omega 3 raises leptin. I'm not sure whether this is a good thing, anymore.)
Matt should leave Jimmy the heck alone. Sorry for the strong language. :nono:
