Summary
The developed world is facing the problem of double epidemics — obesity and diabetes. In the United States, the consumption of added sugars has increased by almost 20 percent over the past few decades. Overconsumption of sucrose causes weight gain, while overconsumption of fructose produces abnormal blood lipid levels and fat deposition in healthy as well as overweight people. Higher sugar consumption also triggers insulin resistance and increases the chances of metabolic syndrome. This study found out that sweeteners with no calorific value like stevia and aspartame are better than sucrose.

Introduction
Consumption of sugar-sweetened foods and beverages produces hyperglycemia or insulin resistance. It can lead to metabolic and hormonal changes that stimulate hunger and promote fat deposition. To address this problem, non-nutritive sweeteners like stevia and aspartame are promoted, as these contain very few calories. But studies on aspartame have provided mixed results. Some studies find aspartame good for weight management, while others suggest that it stimulates appetite and leads to weight gain. Stevia, a natural substance, has been found to have beneficial effects on the blood glucose and insulin levels in humans. The present study tested the effects of stevia, aspartame and sucrose taken before big meals, on the satiety, food intake and glucose and insulin levels, in both lean and obese individuals.

Methodology
* The study involved 19 lean and 12 obese non-smoking individuals not suffering from diabetes, cardiovascular disease, chronic illnesses or depression. Each individual participated in three experiments on different days.
* On test days, the participants ate a standard 469 calorie breakfast. Then, 20 minutes before lunch and dinner, the participants had a preload of 400 grams of food sweetened with either stevia or aspartame or sucrose. During lunch and dinner, they ate as much as they wished.
* The participants reported their hunger and satiety levels on a scale before and after each meal, as well as 30 minutes and every hour after lunch, throughout the afternoon.
* Blood samples were collected immediately before consuming the first preload and lunch, and at intervals of 30 minutes, 1 hour and 2 hours after the test lunch.

Results
* Compared to sucrose as preload, the participants ate 300 calories less when stevia was used; they ate 334 calories less when aspartame was used.
* The participants felt that aspartame had a more pleasant taste than stevia and sucrose. The hunger and satiety levels did not differ between the stevia, aspartame and sucrose users.
* The blood glucose level remained significantly low for the stevia group. Thirty minutes after lunch, the blood glucose was around 96 mg/dl for stevia users and around 106mg/dl for aspartame and sucrose users.
* Plasma insulin levels were also low in stevia users. Thirty minutes after lunch, it was 48 IU/kg in stevia users, while it was around 60 IU/kg in aspartame and sucrose users.

Next steps/Shortcomings
In this study, the eating behavior was measured in a laboratory setting. The results might vary when people eat at home, where there is easily available food and the temptation to eat is greater. The study considered calorie intake during just one day. Whether compensatory overeating occurs the next day at home is not known. Also, there was no control condition excluding a sweetener, to test how sweetness affects food intake.

Conclusion
Food sweeteners like sucrose are a leading cause of excess calories and weight gain. Food sweeteners with low caloric value are increasingly being used to replace sucrose. Compared to sucrose, aspartame and stevia used as a preload appear beneficial to obese or diabetic patients. These substances reduce calorie intake and reduce the plasma glucose and insulin levels. The effect is stronger in stevia users. Stevia is a plant-derived natural substance. Studies have shown no side effects in cases of stevia consumption. The participants in this study felt that their levels of satiety were unchanged by substituting stevia or aspartame. Stevia, consumed 20 minutes before the main meal, can be an effective aid in dietary management of obesity or diabetes. The study also showed that stevia might help with glucose regulation.

For More Information:
Effects of Stevia, Aspartame, and Sucrose on Food Intake, Satiety, Glucose and Insulin Levels
Publication Journal: Appetite, 2010
By Stephen Anton; Corby Martin; Pennington Biomedical Research Center, Baton Rouge, Florida and University of Florida

*FYI Living Lab Reports Are Summaries of the Original Research.