Low- and No-Calorie Sweeteners No Better Than Sugar for Weight Loss

If you want to lose weight and help prevent chronic disease, you may be inclined to reach for foods and drinks made with low- or no-calorie sweeteners over those made with table sugar.

But a study published in January 2019 in The BMJ found no evidence of health benefits from choosing these alternative sweeteners, which include artificial ones, such as aspartame (Nutrasweet, Equal), saccharin (Sweet ’N Low), and sucralose (Splenda), as well as stevia (Truvia, Sweetleaf). The investigation also could not rule out potential harms from these products.

“While nonsugar sweeteners are very widely used, there is no good and unambiguous evidence that they are good for your health,” says study author Joerg Meerpohl, MD, the head of the Institute for Evidence in Medicine at the University of Freiburg in Germany. “This does not preclude some smallish benefits, but it seems it is not a magic bullet.”

How No- and Low-Calorie Alternative Sweeteners Are Used

The Food and Drug Administration considers alternative sweeteners safe if they’re consumed within acceptable daily intake (ADI) levels. Thus, food makers commonly add them to diet drinks, baked goods, frozen desserts, candy, light yogurt, and chewing gum.

In contrast, Dr. Meerpohl says, “Based on current evidence, we also cannot definitively exclude negative health impact. Given that there is no convincing evidence for health benefits, people need to ask themselves whether they want to consume nonsugar sweeteners, particularly in large quantities.”

The Potential Health Benefits of Using Nonsugar Sweeteners

Meerpohl and fellow scientists with the nonprofit research group Cochrane conducted the research to support guidelines on nonsugar sweeteners being developed by the World Health Organization (WHO).

Study authors based their analysis on a review of 56 studies that measured how consuming nonsugar sweeteners affected a wide range of health outcomes in adults and children. These outcomes included weight, blood sugar control, heart disease, and cancer.

Overall, scientists found the sweeteners didn’t significantly lower participants’ weight or appear to affect their risk for disease, but the study results suggested small improvements in body mass index (BMI) and fasting glucose. Fasting glucose levels are measured after a patient has not eaten for at least eight hours and is a measure used to diagnose diabetes. Also, researchers found that people who tended to eat the lowest amounts of nonsugar sweeteners gained less weight than those who ate higher amounts of these sweeteners.

In children, researchers observed a smaller increase in BMI among those who ate nonsugar sweeteners versus sugar, but no difference in body weight. BMI is a measure of body fat based on a weight-to-height ratio.

Researchers noted that most studies analyzed had few participants, were of short duration, and their methodological and reporting quality were limited. “Therefore, confidence in the reported results is limited,” wrote the authors.

Weighing the Pros and Cons of No- and Low-Calorie Sweeteners

While this study found no notable positive or negative effects from choosing alternative sweeteners in lieu of sugar, other studies have found that they may be harmful.

For instance, a review published in November 2017 in the journal Current Gastroenterology Reports stated that “Although artificial sweeteners were developed as a sugar substitute to help reduce insulin resistance and obesity, data in both animal models and humans suggest that the effects of artificial sweeteners may contribute to metabolic syndrome and the obesity epidemic.”

Insulin is a hormone that helps the cells use glucose (blood sugar) for energy, while insulin resistance refers to an inability for the body’s cells to use insulin effectively. Insulin resistance is the hallmark of type 2 diabetes, which causes sugar to accumulate in the blood (called hyperglycemia), increasing the risk for health complications like kidney damage, nerve damage, and blindness.

According to the American Diabetes Association, artificial sweeteners may be a good choice for people with diabetes because they contain fewer calories and carbs. People with diabetes need to count carbs to help keep their blood sugar levels stable.

Betul Hatipoglu, MD, an endocrinologist at the Cleveland Clinic in Ohio who was not involved in the study, says artificial sweeteners are much less likely to spike blood sugar than regular sugar, and some of her patients who have switched from sugary drinks to diet drinks have lost up to 30 pounds.

“I tell patients as far as we know, you can use artificial sweeteners; just make sure you don’t overdo it,” Dr. Hatipoglu says. “Like anything, you need to use moderation.”

One of the best ways to limit either sugar or nonsugar sweetener intake is drink more water, says Hatipoglu. “I tell patients if they want to make their water more flavorful they can infuse it with natural ingredients — I love a combination of strawberries and lemon with basil,” she says.

Osama Hamdy, MD, PhD, medical director of the Obesity Clinical Program and director of the Inpatient Diabetes Program at Harvard Medical School’s Joslin Diabetes Center in Boston, adds, “If you ask me which to use — sugar or nonsugar sweeteners, my answer will be nonsugar sweeteners. But if you ask me if there is any benefit beyond some little weight reduction due to reduction in caloric intake, my answer will be I do not see compelling evidence of any other benefit.”

How the Body Responds to Sugar and Artificial Sweeteners

Dr. Hamdy, who wasn’t involved in the new study, says that sugar is rapidly absorbed and metabolized, resulting in a sudden rise in blood glucose and a strong stimulation of insulin secretion. The insulin promotes storage of fat and thus increases body weight.

“All these effects are weaker or muted in nonsugar sweeteners,” he says. As the American Diabetes Association explains, many of these sweeteners pass through the body without being digested so they provide no extra calories.

So why do some patients who choose these sweeteners over sugar still gain weight or fail to lose weight? Hamdy says that one theory suggests sweeteners change intestinal microbiota (bacteria in intestine) in a way that may promote weight gain, while another idea suggests that the brain reacts in the same to sugar and sweeteners regarding control of body weight.

Although study authors did not examine why or how alternative sweeteners affect weight, Meerpohl speculates that they may increase appetite, leading people to overeat after consuming them.

While Hamdy, Hatipoglu, and Meerpohl all say that rigorous methods of data analysis were applied in the study and the results may be helpful, they also agree that further research is needed to better understand how nonsugar sweeteners may affect an individual’s health. Meerpohl says that his group is currently working on a review to assess the effects of these sweeteners in people with diabetes.