The first question is- if I consume a product that does not contain sugar, will this help me lose weight or prevent me from gaining weight? This is of course what most consumers looking at packaging that says “sugar free” are thinking. Unfortunately, this is not true. These fake sugar products still trigger insulin secretion in humans. Insulin secretion is what causes us to gain weight. Non-nutritive sugars also alter the secretion of the gut hormone incretin which increases glucose absorption in the gut. This means non-nutritive sugars will increase the amount of glucose your body absorbs, and this is how you gain weight. Nonnutritive sugars also upregulate proinflammatory and adipose promoting pathways (this means it increases your chances of getting fat and developing chronic diseases). Finally, these non-sugar products can change the microbiome or bacteria that line your gut. Studies in children of normal weight have shown that consuming products with non-nutritive sugars led to higher sugar intake and weight gain. So, basically these kids did not lose weight but gained weight as they consumed more “sugar free” products.
In pregnancy, women worry that gaining too much weight and consuming too much sugar increases the chance of developing gestational diabetes and all the problems associated with it. Unfortunately, these fake sugar products will not save you from developing gestational diabetes. These fake sugar products are also easily transported through the placenta to the baby and via breast milk. The metabolites of these products can be found in amniotic fluid and the urine of newborns. Their safety in pregnancy is not well established. While the Academy of Nutrition and Dietetics states that non-nutritive sugars are safe in pregnancy, neither the American College of Obstetrics and Gynecology nor the Institute of Medicine have released any statements as to the safety of these products in pregnancy and lactation. We have lots of animal studies, but very few good human studies in pregnancy to establish the safety of these products in pregnant women.
The take home message from this is you are not likely going to lose weight or control weight gain with the use of fake sugars. Also, the safety of these chemicals in pregnancy and breastfeeding are not well established because of the lack of good human studies in pregnancy and lactation. You are better off moderating your regular sugar intake than you are using these “sugar free” products to control weight and optimize your overall gut health.