???These results are consistent with reports showing that high BMI is associated with decreased prefrontal activity at rest and after meal consumption and that obese subjects have an attenuated postprandial deactivation of the hypothalamus. These altered obesity-associated neural responses to food cues may contribute to overeating behavior, especially several hours after consumption of high-carbohydrate meals, a time when glucose often declines significantly below baseline levels.???
Thus, as the authors conclude:
???These findings demonstrate that circulating glucose modulates neural stimulatory and inhibitory control over food motivation and suggest that this glucose-linked restraining influence is lost in obesity.???
They also speculate that:
???Strategies that temper postprandial reductions in glucose levels might reduce the risk of overeating, particularly in environments inundated with visual cues of high-calorie foods.???
One strategy to avoid drops in blood glucose levels is not to allow yourself to go hungry by consuming smaller but more frequent meals. The other is perhaps to chose low-glycemic index foods in order to prevent the ???crash-and-crave??? drive that follows rapid changes in blood glucose levels.
The study, certainly provides further evidence for important ???biological??? differences between non-obese and obese people - while the former experience ???natural??? appetite suppression with high-normal glucose levels, the latter do not experience such a suppression of appetite and will need to resort to conscious restraint - a far more difficult undertaking.
EDIT: I am editing this to add two articles that I have previously shared in more than one PH response previously. I am adding them because they round out the info concerning the BIG differences found in post obese or significantly weight reduced people, so they provide additional and very important info for considering the very different bodies that we , the post-obese and sigificantly weight reduced must manage. And to be clear, the incusion of "potatoes" in the title was tongue in cheek. As per the article,we are talking about foods that stimulate signifcant glucose response.
"As readers will recall, the biology of the post-weight loss state is nothing like the biology of someone who has never lost weight. There are countless ways in which the psychoneurobiology, energy physiology and metabolism in anyone who has lost weight are remarkably different from someone ???naturally??? of that weight.
Simply stated, someone who was 150 lbs and has lost 20 lbs cannot hope to maintain that weight loss by simply eating the same amount of food or doing the same amount of exercise as someone who is ???naturally??? a 130 lbs.
The 150 lbs person who has lost 20 lbs, to maintain their new 130 lbs, has to actually now live like someone who is ???naturally??? a 110 lbs; just eating like someone who is 130 lbs but has never lost weight, will simply result in rapid weight regain.
This is why just cutting out a few ???extra??? calories or walking a few ???extra??? steps is not an effective or sustainable strategy for maintaining weight loss - for any clinically meaningful weight loss (when indicated) - we are looking at cutting hundreds of calories from the diet and adding hours of serious exercise per week - forever!"
"The consistent finding from all such studies is that all individuals or animals in a post-weight-loss state face considerable ???homeostatic pressure??? that aims to drive their weight back to initial levels.
The paper extensively discusses how changes in biological signals of fat stores (e.g. leptin) elicit profound metabolic and behavioural adaptations - a topic that I dealt with extensively in previous posts.
The key findings of increased hunger and appetite, reduced satiety and substantially increased ???fuel efficiency??? have very real underlying biological drivers - drivers powerful enough to ultimately wear down even the most persistent dieter.
As the authors point out - persistent dieting is so difficult because it requires maintaining a remarkably large ???energy gap???"
"One of the key underlying problems is that when people lose weight, their energy expenditure does not simply fall to that of the energy expenditure of a person ???naturally??? at that lower weight - it drops to levels far greater than expected.
Thus, a formerly-obese person burns 20% less calories than a never-obese person of that lower weight - or in other words a 200 lb person, who loses 40 lbs burns about 20% fewer calories than someone who is 160 lbs, but has never been obese. On top of this, the formerly-obese person experiences hunger, cold intolerance, and other behavioural and metabolic changes that make sustaining this lower body weight difficult."
"In a large series of carefully conducted energy balance studies in humans, Leibel examined the impact of weight loss on energy expenditure, energy intake, neuroendocrine function, autonomic physiology, metabolism and brain imaging.
Whereas a short-term increase in body weight by 10 % results in a transient increase in energy expenditure, this returns to baseline, when the weight is lost. This means that weight-loss per se does not reduce energy expenditure.
On the other hand, a 10% drop in body weight immediately reduces energy expenditure by as much as 20%.
Interestingly, this fall in energy expenditure is not simply due to a fall in metabolic rate, but largely due to a decline in activity expenditure. This means that the body ???saves??? energy not simply by turning down the furnace, but by becoming substantially more ???fuel efficient??? during activity. In other words, someone who loses weight, will burn substantially fewer calories for a given amount of exercise than for the same amount of exercise performed before weight loss."
asked byAtkins_witha_loincloth (5477)
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on November 13, 2011
at 11:48 PM
"These altered obesity-associated neural responses to food cues may contribute to overeating behavior, especially several hours after consumption of high-carbohydrate meals, a time when glucose often declines significantly below baseline levels."
In my case, it was definitely true that the fatter I got, the hungrier I got. When I was younger and just overweight, but not obese, I could restrict my food intake fairly easily, and even though standard diets like WW seemed to have zero effect on my body fat, I could stick to them for months and months (of course I'd eventually give up in frustration, since nothing seemed to be happening despite paying the monthly fee and eating less than I really wanted to).
But things changed when I got closer to 200 pounds, and especially at my heaviest, around 220 or so. I'd never cried over food before, but when I was following my nutritionist's 1,200 calorie low-fat, high-whole-grain diet, I had times when I sat in my office crying and hating myself for feeling like I was going to die of starvation waiting for 10:00 am to roll around so I could eat my morning snack of two Ak-Mak crackers, after my 7:00 am breakfast of plain oatmeal and fruit, or non-fat yogurt. I'm not kidding -- the hunger was so overwhelming that all I could think of were those two damn crackers in the ziploc baggie in my purse, and it took every ounce of strength I had to not eat them an hour earlier than I was supposed to.
Good times, good times.
on November 13, 2011
at 06:19 PM
The point is that this is yet another piece of research that says that what the nuero-reg systems of obese/postob ppl do in the presence of normal glucose loads is very different. Lean = satiety ob/postob = HUNGER after those potatoes!
i wonder if this explains the hunger i experience immediately and for several hour after i eat? i have found that if i just ignore it, the hunger goes away. if i eat more to try to satisfy it; it doesn't go away. the only piece that does not fit is that my diet is LC most of the time.
on November 13, 2011
at 06:15 PM
(Do you think that obese and never-obese people have the same response to glucose and that an obese or post obese should just relax and have a potato?) mem
Basically, no I don't. I speak as a less-obese person than 6 months ago. I start my day with meat and fat. Any starchy veggies, including potato, must follow that or my appeptite will fire up big-time. If I "relax and have a potato" by itself I'll slip to a binge within a week because willpower can only hold so long.
Even after 6 months and 30+ pounds lost, I'm still pretty reactive to starch. Therefore, a typical meal for me starts with meat, then non-starchy veggies and 1-2 bites of sweet potato or potato. If I'm having fruit that day, it comes at the end.
If I start a meal with either starch or fruit, I still get the spike-and-crash that makes sensible eating very difficult. If I eat as described above, I'm usually not hungry again until the next day--and I'm hungry for meat first.
on November 16, 2011
at 02:39 PM
As someone who has lost over 100 pounds and still has another 100 to go, this really resonates with me.
My experience is such that, I feel that my "setpoint" has gone down significantly, and that I can comfortably maintain my weight loss if, and this is a BIG if, I throw in a few low calorie days per week. So it ends up being a few days of eating what I want (mostly paleo of course) with a few days of high-fat, ketogenic eating. And this keeps me where I am at.
Ha ha. That is fun. So much fun. NOT.
800 to 1000 calories per day, or less. And the only thing that works anymore is a PSMF.