Phenylalanine and aspartame fail to alter feeding behavior, mood and arousal in men

doi:10.1016/0031-9384(87)90017-5

Physiology & Behavior

Volume 39, Issue 2, 1987, Pages 247-253

https://doi.org/10.1016/0031-9384(87)90017-5 Get rights and content

Abstract

Two experiments were designed to investigate the neurobehavioral effects of phenylalanine (PHE; 0.84, 2.52, 5.04, and 10.08 g) and aspartame (APM; 5.04 and 10.08 g) on energy and macronutrient selection and on subjective feelings of hunger, mood and arousal in normal weight adult males. Neither phenylalanine nor aspartame altered mean energy intakes or macronutrient selection at a lunch begun 60 to 105 min after the amino acids were consumed. During this time, increased (p<0.05) visual analog scale (VAS) scores for emptiness, rumbling, weakness, degree of hunger and urge to eat were found in both experiments, but no treatment effects or interactions were seen for any variable in either experiment. Plasma PHE levels and ratios to other large neutral amino acids (NAA) rose significantly (p<0.05) after all treatments except 0.84 g PHE; plasma tyrosine (TYR) levels increased (p<0.05) only when ⩾2.52 g PHE was given. TYR/NAA ratios were higher (p<0.05) after 2.52 and 5.04 g PHE, and 10.08 g APM. No relationships were found between food intake and plasma amino acid levels. We conclude that, in normal weight men, PHE and APM, in doses up to 10 g, do not affect short-term energy and macronutrient intakes, or subjective feelings of hunger, mood and arousal.

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Effects of l-phenylalanine on energy intake in overweight and obese women: Interactions with dietary restraint status
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l-Phenylalanine (Phe), is a potent releaser of the satiety hormone, cholecystokinin (CCK) and previous studies, conducted primarily in men, show that ingestion of Phe reduces energy intake. The objective of the current study was to test the effects of Phe on energy intake in overweight and obese women. Subjects (n = 32) received three treatments (high-dose (10 g Phe), low-dose (5 g Phe and 5 g glucose) or control (10 g glucose)) 20 min before an ad libitum lunch and dinner meal in a within-subjects’, counterbalanced, double-blind study. No effect of Phe was found, however, interactions with dietary restraint status were detected in post-hoc analyses. Energy intake over the day was 11% lower following high-dose Phe versus control for women classified in the lower tertile of rigid restraint, a subscale of the dietary restraint scale, whereas no effects were noted for women in the middle and upper tertiles. High-dose Phe increased ratings of nausea, however, reduced energy intake in the high-dose condition was noted only for subjects with low nausea ratings. These results suggest that the satiety response to Phe is modulated by rigid restraint status and that reductions in food intake occur independently of Phe's effects on nausea.
Dietary restraint and menstrual cycle phase modulated l-phenylalanine-induced satiety
2008, Physiology and Behavior
l-phenylalanine (Phe) has been shown to elicit release of the gut hormone cholecystokinin (CCK) and reduce energy intake. Furthermore, studies in some animal models demonstrate potentiation of CCK-induced satiety by estradiol (E₂). As E₂ is elevated in the follicular phase, we expected greater satiety effects than in the luteal phase when the effects may be antagonized by concomitant elevations in progesterone (P). Women with low dietary restraint were tested over two cycles and received encapsulated Phe or dextrose (control) during both phases within each cycle. Data from 20 women and 32 menstrual cycles were analyzed. Daily energy intake was suppressed by 9% for Phe compared to control and 8% in the follicular versus luteal phase of the menstrual cycle. Significant three-way interactions showed that the effects of condition and phase differed as a function of status on the rigid dietary restraint subscale. Phe suppressed daily energy intake by 15% relative to control in the follicular phase for women in the lower 50th percentile of rigid restraint, whereas for women in the higher 50th percentile group, Phe reduced energy intake by 15% in the luteal phase. The results replicate previous findings showing effects of cycle phase and Phe on food intake. The interaction between variables suggests that rigid restraint status modulates the satiety response to Phe, possibly through effects of reproductive hormones. Further studies are needed to replicate these findings and examine other aspects of satiety that may be altered by rigid restraint status.
Habitual high and low consumers of artificially-sweetened beverages: Effects of sweet taste and energy on short-term appetite
2007, Physiology and Behavior
Citation Excerpt :
Additionally, the preload used to investigate energy provides sugar and energy, as opposed to sweeteners, so effects may occur as a result of sugar and/or energy. This preload could have been formed from an artificial sweetener plus a tasteless energy supplement such as maltodextrin, however this would have severely reduced the ecological validity of the study, and due to previous reports of the effects of sweeteners on appetite [4–8] was considered unnecessary. A non-sweet/high-energy preload was also not included in the study for reasons of ecological validity.
This study investigated the effects of sweet taste and energy on subsequent short-term appetite in female habitual high and low consumers of artificially-sweetened beverages. The study was based on the proposal that effects of sweet taste on appetite may differ as a result of the habitual experience of sweetness with or without energy. Following a repeated measures design, 10 female habitual high and 10 female habitual low consumers of artificially-sweetened beverages consumed a non-sweet/low-energy, sweet/low-energy, and sweet/high-energy preload, and cumulative test meal intake (gram, kJ.), cumulative total intake (gram, kJ.), and subjective perceptions of appetite were subsequently assessed. Different effects of sweet taste were found in habitual high and low consumers of artificially-sweetened beverages. Low consumers of artificially-sweetened beverages demonstrated an increase in appetite in response to sweet taste, whereas high consumers did not. Effects of energy on appetite did not differ between consumers. The effects of energy are unsurprising. The effects of sweet taste, however, are of interest. The lack of response to sweet taste in high consumers of artificially-sweetened beverages can be explained as a result of the repeated experience of sweetness without energy by these consumers. This lack of response suggests an adaptation to sweet taste as a result of the habitual dietary pattern of these consumers.
Intense sweeteners and sugar replacers in the regulation of food intake and body weight
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Regulatory toxicology and pharmacology
2002, Regulatory Toxicology and Pharmacology
Over 20 years have elapsed since aspartame was approved by regulatory agencies as a sweetener and flavor enhancer. The safety of aspartame and its metabolic constituents was established through extensive toxicology studies in laboratory animals, using much greater doses than people could possibly consume. Its safety was further confirmed through studies in several human subpopulations, including healthy infants, children, adolescents, and adults; obese individuals; diabetics; lactating women; and individuals heterozygous (PKUH) for the genetic disease phenylketonuria (PKU) who have a decreased ability to metabolize the essential amino acid, phenylalanine. Several scientific issues continued to be raised after approval, largely as a concern for theoretical toxicity from its metabolic components—the amino acids, aspartate and phenylalanine, and methanol—even though dietary exposure to these components is much greater than from aspartame. Nonetheless, additional research, including evaluations of possible associations between aspartame and headaches, seizures, behavior, cognition, and mood as well as allergic-type reactions and use by potentially sensitive subpopulations, has continued after approval. These findings are reviewed here. The safety testing of aspartame has gone well beyond that required to evaluate the safety of a food additive. When all the research on aspartame, including evaluations in both the premarketing and postmarketing periods, is examined as a whole, it is clear that aspartame is safe, and there are no unresolved questions regarding its safety under conditions of intended use.
Aspartame: Scientific evaluation in the postmarketing period
2001, Regulatory Toxicology and Pharmacology
Prior to marketing, the safety of the high-intensity sweetener aspartame for its intended uses as a sweetener and flavor enhancer was demonstrated by the results of over 100 scientific studies in animals and humans. In the postmarketing period, the safety of aspartame was further evaluated through extensive monitoring of intake, postmarketing surveillance of anecdotal reports of alleged health effects, and additional research to evaluate these anecdotal reports and other scientific issues. The results of the extensive intake evaluation in the United States, which was done over an 8-year period, and the results of studies done in other countries demonstrated intakes which were well below the acceptable daily intakes set by the FDA and regulatory bodies in other countries, as well as the Joint FAO/WHO Expert Committee on Food Additives. Evaluation of the anecdotal reports of adverse health effects, the first such system for a food additive, revealed that the reported effects were generally mild and also common in the general population and that there was no consistent or unique pattern of symptoms that could be causally linked to consumption of aspartame. Finally, the results of the extensive scientific research done to evaluate these allegations did not show a causal relationship between aspartame and adverse effects. Thus, the weight of scientific evidence confirms that, even in amounts many times what people typically consume, aspartame is safe for its intended uses as a sweetener and flavor enhancer.

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^☆: This research was supported by the International Life Sciences Institute-Nutrition Foundation, Washington, DC.

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ArticlePhenylalanine and aspartame fail to alter feeding behavior, mood and arousal in men☆

Abstract

Brain Res Bull

Eur J Pharmacol

Biochem Pharmacol

Am J Clin Nutr

Am J Clin Nutr

Nutr Res

Am J Clin Nutr

J Psychiatr Res

Am J Clin Nutr

Pharmacol Biochem Behav

Body fat assessed from total body density and its estimation from skinfold thickness: measurements on 481 men and women aged from 16 to 72 years

Br J Nutr

Cholecystokinin-decreased food intake in Rhesus monkeys

Am J Physiol

Behavioral and biochemical effects of tryptophan, tyrosine, and phenylalanine in mice

Psychopharmacology (Berlin)

Protein and amino acids in the regulation of food intake

Restrained eating

Article
Phenylalanine and aspartame fail to alter feeding behavior, mood and arousal in men☆