Polydextrose is a simple synthetic polymer of glucose produced by yeast. It's a popular food ingredient classed as a soluble carbohydrate by the U.S. Food and Drug Administration and Health Canada, since April 2013. It's often used to add extra dietary fiber to food, to cut sugar and fat content, and to increase daily energy levels. It can be added to many foods but is especially good as a sweetener for bread, yogurt, and tea.
It has a low calorific value, so it is good for replacing some sugar. But, it doesn't have the same impact on blood sugar as sugar would, so it's particularly useful for diabetics, who may benefit from its effect on blood sugar. However, people taking medications that affect blood sugar need to be careful about using this because it can raise their blood sugar concentrations too. Also, it isn't generally considered a "nutrient" because it doesn't provide any nutrients, other than the sugar it contains. It's really a sugar substitute.
Polydextrose and dextrose aren't the only polysaccharides that can help to lose weight. They're just two of many different ones. Polysaccharides, including monofructose, also known as FOS, are commonly used as a natural sweetener in soft drinks and diet foods. They're also found in various legumes, including black beans, peas, mushrooms, and yams. One of the properties of FOS is that it provides an energy similar to that provided by simple carbohydrates, without the feeling of hunger.
Polydextrose and dextrose are both derived from the same source, which is glucose. The difference between the two is that one has the side benefit of being able to absorb into the body more slowly, allowing it to maintain a constant level of concentration. This means it will take less time for blood sugar levels to return to normal. If the food ingredient containing this has a low glycemic index (which indicates how fast it breaks down in the system), it will help blood glucose levels stay more stable for a longer period of time. Because the food ingredient with this compound is also a soluble fiber, it can also help regulate blood sugar and reduce the risk of hypoglycemia.
So, does it have any real health benefits? There are certainly some food additives with this compound that have benefits for people with certain conditions, but these benefits must be carefully weighed against the potential side effects of this compound. For example, even though monofructose is a naturally occurring sugar that we all have in common, experts have warned that people with diabetes should not consume large amounts of this sugar because it can cause a drop in blood sugar levels. They recommended that diabetics try to limit their consumption to less than 50g per day, although this limit could be lowered if an appropriate dietary fiber supplement was used. Similarly, experts believe that people who suffer from conditions such as beriberi and hyperglycemia should avoid foods with this compound.