hunger

Hunger ‘not linked to calorie intake’

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Grocery stores are now amassed with prepackaged meals claiming to suppress appetite and keep us feeling fuller for longer. But according to new research, these meals are unlikely to affect our overall calorie intake.

From a review of more than 460 studies, researchers from the University of Sheffield in the United Kingdom found little evidence of a link between how hungry we feel and the amount of calories we consume.

Study leader Dr. Bernard Corfe, from the Molecular Gastroenterology Research Group at Sheffield, and team publish their results in the journal Critical Reviews in Food Science and Nutrition.

In the United States, more than 2 in 3 adults and around one third of children are considered overweight or obese.

The primary cause of overweight and obesity is an energy imbalance – that is, more calories are consumed than the body uses, or “burns,” which results in excess weight.

As such, eating a healthy diet and sticking to the daily recommended calorie intake – around 1,600-2,400 calories for women and 2,000-3,000 calories for men, depending on physical activity – are considered key for weight loss and maintenance.

Few studies found a link between appetite and calorie intake
Appealing to the the desire of many individuals to lose weight through dietary changes are prepackaged meals that claim to have appetite-modifying properties that keep us sated for longer, reducing the need to reach for the unhealthy snacks when hunger bites.

The new study, however, indicates there is no link between appetite and calorie intake, suggesting some food manufacturers may need to rethink their claims.

Dr. Corfe and colleagues came to their conclusion after conducting a review of 462 studies that assessed both appetite and calorie consumption.

The researchers found that only 6 percent of the studies reviewed made a direct statistical comparison between appetite and calorie intake, and only half of these studies found that self-reported appetite correlated with calorie consumption.

The team says these findings indicate that how hungry we feel has no effect on the amount of calories we consume – something that food manufacturers should take into consideration.

“The food industry is littered with products which are marketed on the basis of their appetite-modifying properties. Whilst these claims may be true, they shouldn’t be extended to imply that energy intake will be reduced as a result.

For example, you could eat a meal which claims to satisfy your appetite and keep you feeling full up for a long period of time but nonetheless go on to consume a large amount of calories later on.”

Dr. Bernard Corfe

Dr. Corfe says further research is needed in order to pinpoint precisely what does influence calorie intake; are environmental or social factors involved?

“This will be important to understand how obesity occurs, how to prevent it, and how we need to work in partnership with the food industry to develop improved tests for foods that are genuinely and effectively able to satisfy appetite,” Dr. Corfe adds.

Source: http://www.medicalnewstoday.com/articles/313620.php

Instant oatmeal more filling than oat-based cereal: Study

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Many people love ready-to-eat oat cereal in breakfast but they do not get the feeling of “fullness”. If that is the case then you can switch to instant oatmeal.

A new research has shown that instant oatmeal is more filling than oat-based cereal.

Researchers said that eating a bowl of instant oatmeal for breakfast is more satiating and it helps in managing hunger better than the same amount of calories from oat-based cereal, even when consumed in smaller portions.

Oatmeal has unique characteristics that have an impact on fullness and desire to eat even when matched for calories and ingredients with another breakfast option.

“We found instant oatmeal to be more effective at suppressing appetite compared to the cold cereal, even with a smaller serving size and less calories than previously investigated,” said Frank Greenway from the Pennington Biomedical Research Centre at Louisiana State University in Baton Rouge, Louisiana.

During his experiment, 43 healthy men and women completed the randomised, controlled crossover investigation over their breakfast habits.

The results showed that the participants reported less hunger compared to the RTE cereal after they ate the instant oatmeal.

Instant oatmeal also provided increased fullness and a reduced desire to eat more.

Researchers state that the viscosity of instant oatmeal was higher than the RTE cereal which could explain the differences in hunger and appetite control.

“The new research demonstrates that increased satiety is possible with smaller portions and less calories (150 calories) of instant oatmeal,” Greenway added in a paper published in the Nutrition Journal.

Source: zee news

Slow eating may reduce hunger but not calorie intake

Previous studies suggest that eating speed may affect how many calories the body consumes. But new research suggests that eating speed, rather than caloric intake, may have more of an impact on hunger suppression.

This is according to a study published in the Journal of the Academy of Nutrition and Dietetics.

Investigators from the Department of Kinesiology at Texas Christian University say that previous research has mainly analyzed the link between calorie intake and eating speed in individuals of a healthy weight.

But this new study looked at the relationship between eating speed and energy intake in 35 overweight and obese individuals and compared the results with 35 individuals of a healthy weight.

New research suggests that eating slowly may reduce hunger but may not have a significant impact on calorie intake.
Both groups were required to consume one meal a day within a controlled environment over 2 days. Both meals were the same for each group, and the energy content (calories) and weight of each meal were measured prior to consumption.

For one meal, both groups were asked to eat at a slow pace. During this meal, they were asked to imagine they had time constraints in which to finish, to take small bites, thoroughly chew their meal and pause and set down their cutlery between bites.

For the other meal, both groups were asked to eat their food at a fast pace. They were asked to imagine they had to finish their meal within a certain time frame, take large bites, chew quickly and to not put down their cutlery between bites.

Slow eating ‘may reduce hunger’
Results of the study revealed that both groups felt less hungry an hour after the slow-eating condition, compared with the fast-eating condition.

Dr. Meena Shah, lead author of the study, explains:

“In both groups, ratings of hunger were significantly lower at 60 minutes from when the meal began during the slow compared to the fast-eating condition. These results indicate that greater hunger suppression among both groups could be expected from a meal that is consumed more slowly.”

Both groups also demonstrated a higher water consumption throughout the slow-eating condition, with 12 ounces of water consumed, compared with 9 ounces throughout the fast-eating condition.

Dr. Shah says the higher consumption of water during the slow-eating condition may have caused stomach distention in the participants and therefore may have affected the level of food consumption.

No impact on calorie intake for obese group
However, when analyzing the participants’ calorie intake, the researchers found that only the subjects of a healthy weight saw a reduction in calorie intake after consuming the meal in the slow-eating condition. The obese/overweight group ate 58 calories less, while the normal weight group ate 88 calories less.

“A lack of statistical significance in the overweight and obese group may be partly due to the fact that they consumed less food during both eating conditions compared to the normal-weight subjects,” says Dr. Shah.

She adds that the overweight and obese participants may have felt self-conscious during the meal, and so it is possible that this may have caused them to eat less.

According to the Centers for Disease Control and Prevention (CDC), more than one-third of the US adult population is obese. Obesity rates have increased from 14.5% of the US population in 1971-74 to 35.9% of the population in 2009-10.

Dr. Shah notes that with obesity rates continuing to rise, information on how individuals of a different weight approach and consume food may help in the development of strategies to reduce calorie intake.

But she says that findings from this study show that slowing the speed of eating “may help to lower energy intake and suppress hunger levels and may even enhance the enjoyment of a meal.”

Source: medical news today

Tummy `clock` tells us how much to eat

Scientists have found the first evidence that the nerves in the stomach act as a circadian clock, limiting food intake to specific times of the day. The discovery, by University of Adelaide researchers , could lead to new information about how the gut signals to our brains about when we’re full, and when to keep eating.

In the University’s Nerve-Gut Research Laboratory, Dr Stephen Kentish investigated how the nerves in the stomach respond to stretch, which occurs as a consequence of food intake, at three-hourly intervals across one day. “These nerves are responsible for letting the brain know how much food we have eaten and when to stop eating,” said Kentish, who is the lead author of the paper.

“What we’ve found is that the nerves in the gut are at their least sensitive at time periods associated with being awake. This means more food can be consumed before we feel full at times of high activity, when more energy is required,” Kentish added.

“However, with a change in the day-night cycle to a period associated with sleeping , the nerves in the stomach become more sensitive to stretch, signalling fullness to the brain quicker and thus limiting food intake.

“This variation repeats every 24 hours in a circadian manner, with the nerves acting as a clock to coordinate food intake with energy requirements ,” he said. So far this discovery has been made in lab studies, not in humans. “Our theory is that the same variations in nerve responses exist in human stomachs , with the gut nerves being less sensitive to fullness during the day and more sensitive at night,” he said.

Source: Deccan Chronicle