An interesting correlation that is noted is that artificial sweeteners are associated with obesity, with both forward causation (artificial sweeteners cause obesity) and backwards causation (obese people consume more artificial sweeteners to lose weight) proposed using trend data from NHANES (American survey). In order to satisfy the first proposal, it was then hypothesized that artificial sweeteners can increase appetite and lead to higher caloric consumption.
It should be noted that the above studies look at 'artifical sweeteners' and do not usually discriminate between the non-caloric sweeteners of aspartame, sucralose, saccarhin, acesulfame-potassium and neotame (for more recent data); although data that is conducted on isolated ingredients such a saccharin suggest this phenomena may not apply to just aspartame.
The Cephalic Phase or Anticipatory Phase of digestion is digestion that is stimulated not by food, but by the senses. In this context (for aspartame), it would be any digestive processes that are stimulated by the sensation of sweetness.
A reason this 'Phase' is under investigation is that carbohydrates tend to have an appetite suppressing effect, but sweetness of carbohydrates tends to act in opposition to this (Typically shown with the same amount of carbohydrate having a greater appetite suppression if not as sweet). Logically, taking the enhancing variable away from the suppressing variable should result in enhancement of appetite.
Insulin does not appear to be at all influenced by tasting aspartame or other non-nutritive sweeteners. Which is in accordance with the inability of aspartame to influence insulin secretion in healthy persons, diabetics and those with other various disease states.
Only carbohydrates and possibly saccharin appear to be able to influence insulin from Cephalic Phase senses whereas carbohydrates may do this via direct absorption into the blood via the mouth. Only one study has noted a decrease in blood glucose associated with 500mg aspartame, theoretically through a release in insulin.
One study noted no differences in growth hormone, cortisol, prolactin, or insulin after ingestion of 0.534g aspartame (about 1L of sweetened beverage) when aspartame was paired with a meal.
The satiety hormone CCK, and Glucagon-like Peptide 1 (GLP-1) are also unaffected after aspartame consumption. These hormones, if risen, suppress appetite.
As aspartame ingestion does not influence satiety hormones to a great deal, suppression may be through a slight serum increase in phenylalanine; a component of aspartame.
Few human studies have found increases in subjective (self-report) or demonstrated (eats more) appetite with aspartame. While in contrast, there are some studies which argue a suppression of appetite for aspartame exists. One study conducted in a metabolic ward where obese persons (n=8) were not subject to food restriction found that covert replacement of sugars with aspartame without notifying the subjects of anything resulted in 25% less energy intake (number is more complimenting than practical usage, since calories were removed to accommodate the inclusion of aspartame). This study also noted a nonsignificant increase in food consumption after aspartame was discontinued, and sucrose reinstated.
When investigating weight changes associated with aspartame, none are seen if other variables are controlled. These variables tend to be calories, as some studies have noted that if calories are kept equal that weight can be lost to an equal degree with both diet soda and regular soda. Intervening in a lifestyle using regular soda and replacing it with diet soda, with no dietary controls, does not appear to induce weight loss in normal weight individuals (although it did so in the heavier individuals). One Meta-Analysis concluded no significant effects of any common artificial sweetener on weight loss assuming calories are controlled, this analysis was conducted on youth.
When looking at the overall data, no convincing data exists to conclude that aspartame positively or negatively affects appetite. Based on the metabolic ward study and other interventions which stratify on body weight though, a case could be made for aspartame suppressing appetite in obese persons with little to no effect on normal weight persons (still somewhat lack of evidence for this claim though, small sample sizes and whatnot)
Although aspartame has been insufficiently linked to increasing appetite, saccharin has been somewhat linked to weight gain. One animal study using saccharin to simulate sweet taste without caloric input found blunted thermic responses to food and weight gain. It was noted earlier that practical dosages of saccharin might influence insulin secretion after taste sensation whereas normal doses of aspartame had no influence; the might is based on some research showing the opposite, no influence from saccharin.
- Does chewing gum offer any health benefits?
- Does Garcinia Cambogia help with weight loss?
- Do MCTs or CLA help with appetite reduction?
- Does eating a higher carb diet make you more full?
- 3 Science-based steps to curbing your appetite
- The science behind munchies: cannabis and your appetite
- Propionate – your ally against overeating?
- Does aspartame cause headaches?
- Do artificial sweeteners spike insulin?
- Does diet soda inhibit fat loss?
- Is diet soda bad for you?
- Low-fat vs. low-carb? Major study concludes: it doesn’t matter for weight loss
- Can hypothyroidism lead to fat gain?
- How do I stay out of "starvation mode?"
- Measuring body fat percentage: It's an accuracy thing
- Is my “slow metabolism” stalling my weight loss?
- Does eating at night make it more likely to gain weight?
- The lowdown on intermittent fasting
- I'm not too tired to stuff my face
- Will eating breakfast keep you lean?
- Do you need to detox?
- How do I get a six-pack?
- Is it really that bad to skip breakfast?
- Will my breasts shrink with weight loss?
- How does protein affect weight loss?
- What should you eat for weight loss?
- 5 little-known facts about protein
- Will lifting weights convert my fat into muscle?
- How do I lose fat around my belly?
- Does high-protein intake help when dieting?
- Whey vs soy protein: which is better when losing weight?
- How important is sleep?
- I have lost significant weight and now have loose skin. How can I tighten up my skin?
- Beverage consumption in the US population. J Am Diet Assoc. (2006) Storey ML, Forshee RA, Anderson PA.
- Artificial sweetener use and one-year weight change among women. Prev Med. (1986) Stellman SD, Garfinkel L.
- Fueling the obesity epidemic? Artificially sweetened beverage use and long-term weight gain. Obesity (Silver Spring). (2008) Fowler SP, et al.
- Nonnutritive sweetener consumption in humans: effects on appetite and food intake and their putative mechanisms. Am J Clin Nutr. (2009) Mattes RD, Popkin BM.
- Prevalence of overweight, obesity and extreme obesity among adults: United States, trends 1960-62 through 2005-2006.
- Gain weight by “going diet?” Artificial sweeteners and the neurobiology of sugar cravings.
- Patterns of weight change and their relation to diet in a cohort of healthy women. Am J Clin Nutr. (1990) Colditz GA, et al.
- Evaluation of the influence of intense sweeteners on the short-term control of appetite and caloric intake: a psychobiological approach.
- Intense sweeteners and appetite. Am J Clin Nutr. (1993) Rogers PJ, Blundell JE.
- Sweet taste: effect on cephalic phase insulin release in men. Physiol Behav. (1995) Teff KL, Devine J, Engelman K.
- Physiological mechanisms mediating aspartame-induced satiety. Physiol Behav. (2003) Hall WL, et al.
- Response to single dose of aspartame or saccharin by NIDDM patients. Diabetes Care. (1988) Horwitz DL, McLane M, Kobe P.
- Glucose tolerance, blood lipid, insulin and glucagon concentration after single or continuous administration of aspartame in diabetics. Diabetes Res Clin Pract. (1986) Okuno G, et al.
- Aspartame ingestion with and without carbohydrate in phenylketonuric and normal subjects: effect on plasma concentrations of amino acids, glucose, and insulin. Metabolism. (1990) Wolf-Novak LC, et al.
- Cephalic phase insulin release in healthy humans after taste stimulation. Appetite. (2008) Just T, et al.
- Carrier-mediated transport systems for glucose in mucosal cells of the human oral cavity. J Pharm Sci. (1999) Oyama Y, et al.
- Aspartame and its constituent amino acids: effects on prolactin, cortisol, growth hormone, insulin, and glucose in normal humans. Am J Clin Nutr. (1989) Carlson HE, Shah JH.
- Reanalysis of the effects of phenylalanine, alanine, and aspartame on food intake in human subjects. Physiol Behav. (1994) Rogers PJ, Blundell JE.
- Effect of covert nutritive dilution on the spontaneous food intake of obese individuals: a pilot study. Am J Clin Nutr. (1977) Porikos KP, Booth G, Van Itallie TB.
- Weight control among obese adolescents: a pilot study. Int J Food Sci Nutr. (2007) Williams CL, Strobino BA, Brotanek J.
- Effects of aspartame in young persons during weight reduction. J Toxicol Environ Health. (1976) Knopp RH, Brandt K, Arky RA.
- Effects of decreasing sugar-sweetened beverage consumption on body weight in adolescents: a randomized, controlled pilot study. Pediatrics. (2006) Ebbeling CB, et al.
- Artificial sweeteners: a systematic review of metabolic effects in youth. Int J Pediatr Obes. (2010) Brown RJ, de Banate MA, Rother KI.
- A role for sweet taste: calorie predictive relations in energy regulation by rats. Behav Neurosci. (2008) Swithers SE, Davidson TL.
- Effect of galactose and sugar substitutes on blood insulin levels in normal and obese individuals. J Med. (1976) Ambrus JL, et al.