Answer: Aspartame is keto-friendly, but better sugar-alternatives are available.
Aspartame is one of the most prevalent artificial sweeteners in the US when it comes to low-calorie foods.
A packet of an aspartame-based sweetener like Equal contains only 0.9 g of net carbs and less than one calorie. Because of this, food manufacturers add aspartame to many sugar-free products, including Diet Coke, Orbit gum, and Jell-O instant sugar-free pudding.
Safety is a concern with any artificial sweetener. There's fierce debate over the safety of many sugar substitutes. Eliminating sugar is great, but nobody wants a replacement that's going to cause health complications.
The hype around aspartame isn't all positive, and one popular fear is that aspartame causes cancer. An Italian study of the effects of aspartame on rats suggested a possible link between the sweetener and an increased risk for blood-related cancers, but later studies on humans contradicted those results.
Ultimately, the FDA found that it's safe to use aspartame in foods and beverages. The FDA does warn that a minority of people with a rare hereditary disease called phenylketonuria (PKU) should avoid aspartame, as they can't metabolize it.
For a more natural alternative, consider stevia or monk fruit. Both are all-natural and have nearly zero effect on blood sugar.
Other popular keto-friendly sweeteners include erythritol and xylitol. They're sugar alcohols, which humans can't digest, so you get the sweetness without the carbs.