Sweet but Not Sugar: What You Should Know About Non-Nutritive Sweeteners

As a registered dietitian, I get questions about sweeteners all the time. Whether it’s a splash in your morning coffee, a sugar-free yogurt, or that zero-calorie soda, non-nutritive sweeteners (NNS) have become everyday items in many kitchens. But are they safe? Are they healthy? And do they actually help with weight loss or blood sugar control?

Let’s unpack the science and help you make informed choices about these sugar substitutes.

What Are Non-Nutritive Sweeteners?

Non-nutritive sweeteners are substances that provide little to no calories and are much sweeter than table sugar (sucrose). You only need a tiny amount to sweeten your food or drink. Common examples include:

• Aspartame (Equal, NutraSweet)

• Sucralose (Splenda)

• Stevia (Truvia, Stevia in the Raw)

• Saccharin (Sweet’N Low)

• Acesulfame potassium (Ace-K)

• Monk fruit extract (Luo Han Guo)

The Big Question: Are They Safe?

The short answer: Yes, in moderation.

All approved NNS have been reviewed by major health authorities like Health Canada, the U.S. FDA, and the European Food Safety Authority. Each has an Acceptable Daily Intake (ADI), which is the maximum amount considered safe to consume daily over a lifetime. For context, you'd have to drink dozens of diet sodas per day to reach that level.

That said, not everyone reacts the same way. Some people report headaches or digestive upset from certain sweeteners, like aspartame or sugar alcohols (which are technically low-calorie, but not non-nutritive).

Health Benefits: Are They Actually Better Than Sugar?

There’s solid evidence that replacing added sugars with NNS can help:

• Reduce overall calorie intake

• Improve blood sugar control in people with diabetes

• Lower the risk of dental cavities

But—and this is important—it depends on what else you’re eating. If you’re using NNS to cut sugar in coffee but still eating lots of ultra-processed foods, the overall benefit may be limited.

What About Weight Loss?

NNS can support weight loss efforts when used as part of a healthy, balanced diet. They’re not a magic bullet, and they won’t suppress cravings for sweets long-term if your diet is still heavily processed or lacking in fiber, protein, and healthy fats.

Some studies even suggest that NNS may increase cravings for sweet foods in certain people, possibly leading to overeating later. The key is awareness and using them as a tool—not a crutch.

Gut Health: A Gray Area

Emerging research suggests that some NNS, like sucralose or saccharin, may affect gut bacteria. The findings are preliminary and based largely on animal studies, but it's an area of growing interest. Stevia and monk fruit may have a more favorable gut profile, though more human data is needed.

If gut health is a concern, it might be worth experimenting with different options or limiting use until we know more.

Bottom Line: Should You Use Them?

Here’s my take as a dietitian:

• Occasional use? Totally fine.

• Trying to reduce added sugar? They can help.

• Concerned about safety? Trust the science—it supports moderate use.

• Prefer to go “all natural”? That’s fine too. Whole foods first is always a good policy.

My advice: Listen to your body. If a sweetener works for you, great. If it causes discomfort or triggers sugar cravings, it might be worth cutting back or choosing natural alternatives like fruit to satisfy your sweet tooth.

Have questions about how sweeteners fit into your diet? Feel free to drop a comment or book a 1:1 with me—let’s talk about what works best for you.