Scientific Studies Show Aspartame is Beneficial in Weight Control

Some researchers have speculated that low-calorie sweeteners can affect appetite and caloric intake via postingestive effects. The theory holds that when low-calorie sweeteners bypass the sweet taste, i.e., when administered in capsule form, they affect certain hormones involved in appetite regulation.

In two separate clinical studies, Drs. Blundell, Rogers and colleagues investigated the effects of encapsulated aspartame on motivation to eat and caloric intake.

• In the first study, food intake was measured in 27 normal-weight individuals following preloads of 234 or 470 mg of encapsulated aspartame, 234 mg of aspartame dissolved in water, or a placebo (control) (Rogers et al., 1990).
  
  
• The encapsulated aspartame reduced motivation to eat and significantly reduced calorie intake one hour later compared with both the aspartame solution and control preloads. The 234 mg dose reduced intake by between 9 and 14 percent (138 and 175 Calories). The 470 mg dose had a similar effect, reducing intake by 150 Calories. The aspartame solution and control preloads did not significantly alter motivational ratings or food intake.
  
  
• It should be noted that Blundell’s data in the study regarding motivation to eat are contradicted by those of his previous two studies where he reported that aspartame in water stimulates appetite. The researchers concluded: “The results provided clear evidence of a predominant postingestive inhibitory action of aspartame on appetite. . ..”
  
  
• In a subsequent double-blind study, Blundell and his colleagues (Rogers et al., 1991) measured hunger and food intake in 16 adults following a preload of encapsulated aspartame or its breakdown components, L-aspartic acid or L-phenylalanine. On the same day for four consecutive weeks, the subjects were given either 200 mg L-aspartic acid, 200 mg L-phenylalanine, 400 mg aspartame or placebo one hour before a self-selected test meal. None of the treatments had a significant effect on hunger, either before or following the test meal.
  
  
• However, the aspartame treatment reduced food intake at the test meal by 15 percent compared with the placebo, while aspartame’s components had no significant effect on intake. Aspartame also did not result in a rebound increase in hunger in the postmeal interval (3 1/2 hours).
  
  
• Noting the absence of increased hunger despite the reduced intake, the researchers concluded: “This suggests that aspartame may act to intensify the satiating effects of ingested food.” Blundell and co-workers simultaneously believe that aqueous solutions of aspartame stimulate appetite, but aspartame in capsules reduces appetite.

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