Sugars in solid versus liquid form - does it matter?
To answer this question, 15 men and women were recruited for a short cross-over trial designed to compare the effects of equicaloric liquid and solid carbohydrate sweeteners on food intake. All participants were in their twenties and in the healthy weight range.
The trial consisted of two four-week interventions, separated by a four-week washout period and cross-over. Once a week during the two trial phases the participants presented themselves to the investigators to be weighed and supplied with weekly rations of their daily 450 kcal sweeteners. The solid load consisted of sucrose-sweetened jelly beans, and the liquid load of HFCS-sweetened soda.The
participants were free to decide when to take their daily loads, and when and what to eat. Calorie intake was estimated from self-assessments of food consumption.
Analysis of the food questionnaires indicated that during their solid phase the subjects fully compensated for the energy content of their preload; the total calorie intake from food plus test sweetener was equal to the pre-trial food energy intake. This was not the case, however, during their liquid trial phase, where food intake remained unchanged, i.e. the sweetened drink added to the total calories.
While conclusions based on self-reporting of food eaten are always questionable, these were within-subject comparisons, i.e. the same bias was likely present in their estimate of food intake after liquid and after solid preloading. Furthermore, the estimated energy intakes were consistent with measured changes in body weight. The participants experienced significant weight gains during the liquid trial phase, but not during the solid trial phase, consistent with an excess energy intake in the liquid phase.
It appears therefore that caloric sweeteners contribute to weight gain if consumed in drinks, but not in solid food.
Fructose and glucose affect appetite and food intake differently
Two hormones, insulin and leptin, act as satiety signals in the brain and thus are critical to energy homeostasis. Both insulin and leptin circulate in the blood at levels proportional to body fat content, and enter the central nervous system in proportion to their plasma levels. Low hormone levels increase appetite, and high levels act to reduce energy intake.
Insulin levels rise in response to blood glucose. Insulin-mediated entry of glucose into adipocytes (fat cells) in turn causes the release of leptin. In other words, both insulin and leptin levels react to glucose concentrations. Fructose, on the other hand, does not trigger insulin release. This in turn means that fructose doesn′t affect leptin levels either. Since it increases neither insulin nor leptin levels, fructose consumption does not generate the same satiety signals as glucose. The result is overeating and weight gain.
Summary
To summarize, the rise in obesity rates with increasing HFCS consumption was no coincidence. The increased popularity of soft drinks and HFCS-sweetened convenience foods led to a rapid increase in fructose consumption. It was this excessive fructose intake that fuelled the rapid weight gain, since fructose does not generate the same satiety signals as glucose. It is likely that sweetened drinks are worse than sweet solid foods, and that sucrose has the same effect as high fructose corn syrup.
Most studies of the effects of calorically sweetened liquids on appetite and weight gain looked at soft drinks. However, fruit juices and drinks also contain added sweeteners, typically HFCS, i.e. they pose the same obesity risk. Switching to noncalorically sweetened soft drinks isn′t the answer either, since artificial sweeteners like aspartame come with problems of their own.
Of course fruit also contains fructose ("fruit sugar"), but this obviously doesn′t mean that one should stop eating fruit. It doesn′t contain nearly as much fructose as sweetened drinks and it is a valuable source of phytonutrients and fiber, whereas soft drinks provide little more than empty calories.
Clearly, one of the best things we can do for our health is to stop drinking soft drinks. -- from naturalnews.com
To answer this question, 15 men and women were recruited for a short cross-over trial designed to compare the effects of equicaloric liquid and solid carbohydrate sweeteners on food intake. All participants were in their twenties and in the healthy weight range.
The trial consisted of two four-week interventions, separated by a four-week washout period and cross-over. Once a week during the two trial phases the participants presented themselves to the investigators to be weighed and supplied with weekly rations of their daily 450 kcal sweeteners. The solid load consisted of sucrose-sweetened jelly beans, and the liquid load of HFCS-sweetened soda.The
participants were free to decide when to take their daily loads, and when and what to eat. Calorie intake was estimated from self-assessments of food consumption.
Analysis of the food questionnaires indicated that during their solid phase the subjects fully compensated for the energy content of their preload; the total calorie intake from food plus test sweetener was equal to the pre-trial food energy intake. This was not the case, however, during their liquid trial phase, where food intake remained unchanged, i.e. the sweetened drink added to the total calories.
While conclusions based on self-reporting of food eaten are always questionable, these were within-subject comparisons, i.e. the same bias was likely present in their estimate of food intake after liquid and after solid preloading. Furthermore, the estimated energy intakes were consistent with measured changes in body weight. The participants experienced significant weight gains during the liquid trial phase, but not during the solid trial phase, consistent with an excess energy intake in the liquid phase.
It appears therefore that caloric sweeteners contribute to weight gain if consumed in drinks, but not in solid food.
Fructose and glucose affect appetite and food intake differently
Two hormones, insulin and leptin, act as satiety signals in the brain and thus are critical to energy homeostasis. Both insulin and leptin circulate in the blood at levels proportional to body fat content, and enter the central nervous system in proportion to their plasma levels. Low hormone levels increase appetite, and high levels act to reduce energy intake.
Insulin levels rise in response to blood glucose. Insulin-mediated entry of glucose into adipocytes (fat cells) in turn causes the release of leptin. In other words, both insulin and leptin levels react to glucose concentrations. Fructose, on the other hand, does not trigger insulin release. This in turn means that fructose doesn′t affect leptin levels either. Since it increases neither insulin nor leptin levels, fructose consumption does not generate the same satiety signals as glucose. The result is overeating and weight gain.
Summary
To summarize, the rise in obesity rates with increasing HFCS consumption was no coincidence. The increased popularity of soft drinks and HFCS-sweetened convenience foods led to a rapid increase in fructose consumption. It was this excessive fructose intake that fuelled the rapid weight gain, since fructose does not generate the same satiety signals as glucose. It is likely that sweetened drinks are worse than sweet solid foods, and that sucrose has the same effect as high fructose corn syrup.
Most studies of the effects of calorically sweetened liquids on appetite and weight gain looked at soft drinks. However, fruit juices and drinks also contain added sweeteners, typically HFCS, i.e. they pose the same obesity risk. Switching to noncalorically sweetened soft drinks isn′t the answer either, since artificial sweeteners like aspartame come with problems of their own.
Of course fruit also contains fructose ("fruit sugar"), but this obviously doesn′t mean that one should stop eating fruit. It doesn′t contain nearly as much fructose as sweetened drinks and it is a valuable source of phytonutrients and fiber, whereas soft drinks provide little more than empty calories.
Clearly, one of the best things we can do for our health is to stop drinking soft drinks. -- from naturalnews.com
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