Saturday, November 13, 2010

Lose weight by drinking water

With the epidemic of obesity sweeping the nation Americans are looking for safe and effective ways to lose weight without countless hours of being in the gym or the dangerous side effects of diet pills.
The good news is that drinking two glasses of water before each meal can be a very effective way for people to shed those unwanted pounds with minimal effort, because there are many cases where people overeat not because they are hungry but because they are thirsty. The hunger mechanism in the body is controlled by hormones. The problem with hormones controlling this mechanism is that their effects are not instantaneous. Many of you can recall a Thanksgiving day meal when you are eating your second serving of turkey and mashed potatoes when all of a sudden you felt like you were so full that you were going to burst. The reason for this is because you may have been full 30 minutes ago but it took time for those hormones to send signals to your brain letting you know that you are full.
The feelings of hunger and thirst come from the basic needs center of our brain located in the thalamus. Certain studies have shown that water preloading before a meal can decrease the amount of calories consumed during a meal and increase satiety (feeling of being full) after a meal. Considering these hunger or thirst cravings in the body are derived by similar mechanisms in the brain it has been hypothesized that many people mistake thirst for hunger and if the hydration needs of the body are not met then the individual is more likely to consume a larger amount of calories during a meal. The following are conclusions derived from some of these studies:
Thirty minutes before the meal, subjects were given either a 500-mL water preload or no preload. Energy intake at each meal was covertly measured. Meal energy intake was significantly less in the water preload condition as compared with the no-preload condition (500+/-32 vs 574+/-38, respectively; P=0.004), representing an approximate 13% reduction in meal energy intake (consumption of calories). The percentage reduction in meal energy intake following the water preload was not related to sex, age, body mass index, or habitual daily water consumption (all P>0.05). Given the high prevalence of overweight and obesity among older adults, future studies should determine whether premeal water consumption is an effective long-term weight control strategy for older adults.(1)
Meal energy intake after the water preload (WP) was significantly reduced relative to the non-preload (NP) condition in the older subjects (682 + 53 vs. 624 +/- 56 kcal for NP and WP, respectively; p = 0.02). This effect was caused primarily by the reduction in meal energy intake after water consumption in older men. Hunger ratings were lower and fullness ratings were higher in older compared with younger adults (p < 0.01). Fullness ratings were higher in the WP condition compared with the NP condition for all subjects (p = 0.01). No age differences in thirst were detected during the test meals. DISCUSSION: Under acute test meal conditions, pre-meal water consumption reduces meal energy intake in older but not younger adults. Because older adults are at increased risk for overweight and obesity, intervention studies are needed to determine whether pre-meal water consumption is an effective long-term weight management strategy for the aging population. (2)
With Americans drinking less water and more sugary and caffeinated beverages it is absolutely essential that we drink an adequate amount of water to help keep us hydrated and allow our body to eliminate toxins. If you are wondering how much water you should be drinking visit this website and click the nutrition tab and go to water to find out how much water you need to consume a day to stay properly hydrated. You may be surprised to find out how much water you should be drinking.
1)Davy BM, Dennis EA, Dengo AL, Wilson KL, Davy KP. “Water consumption reduces energy intake at a breakfast meal in obese older adults.”J Am Diet Assoc. 2008 Jul;108(7):1236-9.
2)Van Walleghen EL, Orr JS, Gentile CL, Davy BM. “Pre-meal water consumption reduces meal energy intake in older but not younger subjects.”Obesity (Silver Spring). 2007 Jan;15(1):93-9.

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