Aspartame is a nonnutritive artificial sweetener. It is used as a sugar substitute in soft drinks, candy, chewing gum, and low-calorie foods and is also available as a tabletop sweetener (e.g., Canderel, Hermesetas Gold, NutraSweet, and Pal Sweet).
Aspartame is most often used for
Last Updated:April 2, 2024
Aspartame is a nonnutritive artificial sweetener made from the amino acids L-aspartic acid and L-phenylalanine and is commonly used as a sugar substitute in various foods and beverages, including soft drinks and low-calorie products. It is available under several brand names, such as Canderel and NutraSweet.
Aspartame is claimed to help suppress appetite, aid in weight loss maintenance, and improve cardiometabolic health, which makes it popular among people who are on energy restriction diets. However, current evidence does not support long-term health benefits from aspartame in terms of energy intake, weight loss, or cardiometabolic health.
Aspartame's main drawbacks include its potential risk for individuals with phenylketonuria because it releases phenylalanine upon digestion, which can cause severe brain problems in these individuals. Additionally, although some studies suggest a possible association between aspartame and cancer, the evidence is inconsistent, which has led regulatory bodies to conclude that it is safe for consumption at current exposure levels, though further research is needed.
Aspartame is metabolized into the amino acids L-aspartic acid and L-phenylalanine, which can be further broken down into small quantities of methanol, formaldehyde, and formic acid and potentially lead to adverse effects at high doses. Although aspartame activates sweet taste receptors and may influence appetite regulation, its precise effects and mechanisms in the body, including any potential associations with cancer, remain unclear and require further investigation.
Dosage Information
In the US, aspartame and other artificial sweeteners are regulated by the FDA, and products containing aspartame must be approved before they can be used. Because of the potential health risks of aspartame consumption, the FDA has set an acceptable daily intake, which is the maximum amount considered safe to consume each day over a person's lifetime.
In the US, the FDA has set the acceptable daily intake for aspartame at 50 milligrams per kilogram of body weight per day (mg/kg/day). Meanwhile, the EFSA and the Joint Food and Agriculture Organization and World Health Organisation Expert Committee on Food Additives (JECFA) have set the acceptable daily intake for aspartame at 40 mg/kg/day.[2][3]
To put these acceptable daily intake values into context, a person weighing 70 kg would have to consume approximately 9–14 cans of diet soda per day to exceed an intake level of 40 mg/kg/day.
Unlock the full potential of Examine
Diet soda does not inhibit fat loss and may even help suppress appetite, which could aid in fat loss. However, it does not directly induce fat loss.
First, let's define 'diet soda' as any drink that is sweetened with low to no calorie sweeteners (like sucralose, aspartame, acesulfame-potassium, etc.) in order to taste like regular (sugared) soda.
In short, there are no direct causative studies that show the use of artificial sweeteners slows your metabolism or promotes fat storage.[46]
The CHOICE randomized study, lasting 6 months and observing how different diet changes affect weight loss adherence, found that diet soda is an effective substitution for regular soda and had no significant differences in health or weight loss relative to water.[47]
Data from the NHANES (03-04) study suggest that increased servings of non-caloric beverages are not related to an increase in total calories.[48] Additionally, the PREMIER trial found that a reduction in intake of non-caloric beverage is not associated with weight loss.[49]
The real problem is that people tend to under-estimate caloric intake. By thinking about the zero calories in the soda, they end up eating an excess of calories, thus increasing fat storage[50]. This makes the well known correlation (relationship) between diet soda and obesity; one does not cause the other, but they tend to co-exist. Drinking diet soda does not make one fat, but people with obesity tend to drink diet soda.
In regards to insulin, diet soda can potentially increase insulin secretion by both an anticipatory response and the artificial sweetener aspartame can (through the amino acid, phenylalanine). However, both of these insulin spikes are too small to matter practically, and the latter mechanism doesn't seem to occur at all with many commonly ingested dosages.
As mentioned on our Aspartame and Appetite page, aspartame (via phenylalanine) might also suppress appetite.
Research indicates that diet soda is generally not harmful to metabolic health or body composition, although further controlled trials are necessary to investigate any potential negative effects.
Currently available research into diet soda and long-term health risks is insufficient, although there are specific areas where risks are unlikely. Contrary to popular belief, diet soda (defined as calorie free carbonated beverages sweetened with aspartame, sucralose, acesulfame-potassium, or other non-caloric or minimally caloric sweeteners) doesn't inhibit fat loss, or spike insulin levels.
Current research that attempts to link diet soda with type 2 diabetes and metabolic syndrome[51][52] did not have equal caloric consumption. Excess caloric consumption has a direct correlation with many health issues, and in fact one of the studies[51] distinctly states:
Consequently, the previously observed diet soda–metabolic syndrome associations are generally speculated to be the result of residual confounding by other dietary behaviors, lifestyle factors, or demographic characteristics (1,2). Biological mechanisms possibly explaining these associations are few and largely focus on artificial sweeteners in beverages/foods increasing the desire for (and consumption of) sugar-sweetened, energy-dense beverages/foods (3) or disrupting consumers' ability to accurately estimate energy intake and remaining energy needs (4). Thus, diet soda consumption may result in overconsumption, increased body weight, and consequent metabolic dysfunction.
In short, many people who have bad diets may consume diet soda in an attempt to do "less damage" - this could result in an incorrect association of diet soda consumption with health conditions.
That was most likely a survey or epidemiological research. This is research that aims to find correlations (relationships) between two variables, and sets up future studies to find which variable causes what.
There are many studies that note that diet soda is frequently consumed by unhealthy people,[51][52] but no studies that compare people with equivalent diets. One study (Northern Manhattan Study) was able to control a fair number of variables and found a weak correlation between diet soda and vascular events, but these differences disappeared when 'pre-existing health conditions' were considered.[53]
When comparing diet soda against other non-caloric beverages in an intervention study, and you control the rest of the diet, no difference in weight loss is noted. This suggests that the problem is likely the habits of people who drink diet soda, rather than the diet soda itself.[51] The Northern Manhattan study suggested that diet soda use may be correlated with disease as it its consumption was an attempt by (already unhealthy) individuals to reduce calories and take control of their health.[53]
Soda (in general) has been linked to poor dental health numerous times, especially children.[54][55] Although sucrose (sugar) plays a major role, the general acidity of diet sodas can also negatively influence dental health.[54] Overconsumption of soft drinks without adequate dental intervention may result in cavities and yellowing of teeth, and this applies to both sugared and diet sodas; although sugared are worse in this regard.[56]
Like most things, overconsumption may not be a good idea, especially for your teeth. Otherwise if you want to enjoy a Diet Coke, Coke Zero, Diet Pepsi, or whatever diet soda you enjoy most, don't feel guilty about it.
Full FAQ and database update
We fully updated this page, and have added a number of new FAQs, including ones about how aspartame is made, whether it causes headaches and cancer, and how industry involvement may influence the findings of the studies we cite.
