The obesity model is flawed
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@klaus said in The obesity model is flawed:
Show me the studies which prove that low-carb high-fat diets work better than other diets with the same total calorie consumption.
https://www.bmj.com/content/363/bmj.k4583
Participants 164 adults aged 18-65 years with a body mass index of 25 or more.
Interventions After 12% (within 2%) weight loss on a run-in diet, participants were randomly assigned to one of three test diets according to carbohydrate content (high, 60%, n=54; moderate, 40%, n=53; or low, 20%, n=57) for 20 weeks. Test diets were controlled for protein and were energy adjusted to maintain weight loss within 2 kg. To test for effect modification predicted by the carbohydrate-insulin model, the sample was divided into thirds of pre-weight loss insulin secretion (insulin concentration 30 minutes after oral glucose).
Main outcome measures The primary outcome was total energy expenditure, measured with doubly labeled water, by intention-to-treat analysis. Per protocol analysis included participants who maintained target weight loss, potentially providing a more precise effect estimate. Secondary outcomes were resting energy expenditure, measures of physical activity, and levels of the metabolic hormones leptin and ghrelin.
Results Total energy expenditure differed by diet in the intention-to-treat analysis (n=162, P=0.002), with a linear trend of 52 kcal/d (95% confidence interval 23 to 82) for every 10% decrease in the contribution of carbohydrate to total energy intake (1 kcal=4.18 kJ=0.00418 MJ). Change in total energy expenditure was 91 kcal/d (95% confidence interval −29 to 210) greater in participants assigned to the moderate carbohydrate diet and 209 kcal/d (91 to 326) greater in those assigned to the low carbohydrate diet compared with the high carbohydrate diet. In the per protocol analysis (n=120, P<0.001), the respective differences were 131 kcal/d (−6 to 267) and 278 kcal/d (144 to 411). Among participants in the highest third of pre-weight loss insulin secretion, the difference between the low and high carbohydrate diet was 308 kcal/d in the intention-to-treat analysis and 478 kcal/d in the per protocol analysis (P<0.004). Ghrelin was significantly lower in participants assigned to the low carbohydrate diet compared with those assigned to the high carbohydrate diet (both analyses). Leptin was also significantly lower in participants assigned to the low carbohydrate diet (per protocol).
Conclusions Consistent with the carbohydrate-insulin model, lowering dietary carbohydrate increased energy expenditure during weight loss maintenance. This metabolic effect may improve the success of obesity treatment, especially among those with high insulin secretion.
@george-k said in The obesity model is flawed:
@klaus said in The obesity model is flawed:
Show me the studies which prove that low-carb high-fat diets work better than other diets with the same total calorie consumption.
That's a start.
However, from what I understand, the majority of studies on the subject so far have shown no significant effect, see e.g. this analysis, which claims that the hypothesis underlying these diets has been experimentally falsified:
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@george-k said in The obesity model is flawed:
@klaus said in The obesity model is flawed:
Show me the studies which prove that low-carb high-fat diets work better than other diets with the same total calorie consumption.
That's a start.
However, from what I understand, the majority of studies on the subject so far have shown no significant effect, see e.g. this analysis, which claims that the hypothesis underlying these diets has been experimentally falsified:
@klaus said in The obesity model is flawed:
That's a start.
However, from what I understand, the majority of studies on the subject so far have shown no significant effect, see e.g. this analysis, which claims that the hypothesis underlying these diets has been experimentally falsified:
Couple of points:
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That
studyreview (and I can only access the abstract) is now 4 years old, and the data are presumably even older. -
They report on two (TWO) inpatient studies that negate the hypothesis. How many people were studied? Were they double blind?
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The argument that the carb-insulin model is too simplistic is laughable, simply because the "calories-in/calories-out" model is even more simplistic.
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The references cited are even older. Though, I get the impression the are not references cited in the review.
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The BMJ article I cited studied 164 adults for almost 6 months. That's a pretty good, long study. I doubt that the studies cited in this review were as far-ranging. You know a lot more about statistics than I ever will...I'd love to see their data.
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Because their review of two studies that support their hypothesis, the authors claim that everyone else is lying? That's what falsified means, right?
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@klaus said in The obesity model is flawed:
That's a start.
However, from what I understand, the majority of studies on the subject so far have shown no significant effect, see e.g. this analysis, which claims that the hypothesis underlying these diets has been experimentally falsified:
Couple of points:
-
That
studyreview (and I can only access the abstract) is now 4 years old, and the data are presumably even older. -
They report on two (TWO) inpatient studies that negate the hypothesis. How many people were studied? Were they double blind?
-
The argument that the carb-insulin model is too simplistic is laughable, simply because the "calories-in/calories-out" model is even more simplistic.
-
The references cited are even older. Though, I get the impression the are not references cited in the review.
-
The BMJ article I cited studied 164 adults for almost 6 months. That's a pretty good, long study. I doubt that the studies cited in this review were as far-ranging. You know a lot more about statistics than I ever will...I'd love to see their data.
-
Because their review of two studies that support their hypothesis, the authors claim that everyone else is lying? That's what falsified means, right?
@george-k said in The obesity model is flawed:
@klaus said in The obesity model is flawed:
That's a start.
However, from what I understand, the majority of studies on the subject so far have shown no significant effect, see e.g. this analysis, which claims that the hypothesis underlying these diets has been experimentally falsified:
Couple of points:
-
That
studyreview (and I can only access the abstract) is now 4 years old, and the data are presumably even older. -
They report on two (TWO) inpatient studies that negate the hypothesis. How many people were studied? Were they double blind?
-
The argument that the carb-insulin model is too simplistic is laughable, simply because the "calories-in/calories-out" model is even more simplistic.
-
The references cited are even older. Though, I get the impression the are not references cited in the review.
-
The BMJ article I cited studied 164 adults for almost 6 months. That's a pretty good, long study. I doubt that the studies cited in this review were as far-ranging. You know a lot more about statistics than I ever will...I'd love to see their data.
-
Because their review of two studies that support their hypothesis, the authors claim that everyone else is lying? That's what falsified means, right?
The guy who wrote that review was part of the team of a $40 million project to prove that low-carb diets work, which ultimately failed.
https://www.wired.com/story/how-a-dollar40-million-nutrition-science-crusade-fell-apart/
I don't think a single new study changes much. It's a start or maybe a reason to do follow-up studies. But thousands of studies on these things are published every year. IMO, one would need a somewhat consistent body of studies by various researchers, with various funding sources and various potential hidden agendas, to really make a point here.
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@george-k said in The obesity model is flawed:
@klaus said in The obesity model is flawed:
That's a start.
However, from what I understand, the majority of studies on the subject so far have shown no significant effect, see e.g. this analysis, which claims that the hypothesis underlying these diets has been experimentally falsified:
Couple of points:
-
That
studyreview (and I can only access the abstract) is now 4 years old, and the data are presumably even older. -
They report on two (TWO) inpatient studies that negate the hypothesis. How many people were studied? Were they double blind?
-
The argument that the carb-insulin model is too simplistic is laughable, simply because the "calories-in/calories-out" model is even more simplistic.
-
The references cited are even older. Though, I get the impression the are not references cited in the review.
-
The BMJ article I cited studied 164 adults for almost 6 months. That's a pretty good, long study. I doubt that the studies cited in this review were as far-ranging. You know a lot more about statistics than I ever will...I'd love to see their data.
-
Because their review of two studies that support their hypothesis, the authors claim that everyone else is lying? That's what falsified means, right?
The guy who wrote that review was part of the team of a $40 million project to prove that low-carb diets work, which ultimately failed.
https://www.wired.com/story/how-a-dollar40-million-nutrition-science-crusade-fell-apart/
I don't think a single new study changes much. It's a start or maybe a reason to do follow-up studies. But thousands of studies on these things are published every year. IMO, one would need a somewhat consistent body of studies by various researchers, with various funding sources and various potential hidden agendas, to really make a point here.
@klaus said in The obesity model is flawed:
I don't think a single new study changes much. It's a start or maybe a reason to do follow-up studies. But thousands of studies on these things are published every year. IMO, one would need a somewhat consistent body of studies by various researchers, with various funding sources and various potential hidden agendas, to really make a point here.
Agreed. It's a start.
And thanks for linking the "Wired" article. Interesting stuff.
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