Stevia is a natural sweetener extracted from the leaves of Stevia rebaudiana Bertoni, a shrubby plant that grows in the rainforests of South America. Stevia leaves contain naturally sweet substances called stevioside, 6 different rebaudiosides (labelled A through to F) and dulcoside, which together make the leaves at least 30 times sweeter than cane sugar. Among the steviol glycosides, stevioside, rebaudioside A and rebaudioside C have the highest concentration and are on average 250-300 times sweeter than sucrose. These substances can be extracted from the leaves and concentrated into a liquid or added to other granular sweeteners (eg erythritol) to create sugar substitutes that can aid a weight loss diet.
Stevia is available as dried leaves (containing 10% stevioside), powdered extract or liquid extract (dark or clear). One or two dried leaves can be added to your tea-pot during brewing. Powdered leaves can be used in cooking or sprinkled on a bowl of fresh fruit to taste. Just a pinhead sized quantity is needed to sweeten a cup of tea or coffee.
Stevia has a delicious, refreshing taste, negligible calories and does not leave an unpleasant aftertaste like some artificial sweeteners.
Stevia is the sweetener of the future. Because you do not metabolise the sweet chemicals, they offer a calorie-free natural alternative to sugar, and can be used freely by people with diabetes. What’s more, as the sweet components do not break down on heating, Stevia can also be used in cooking and baking.
Stevia is exceptionally helpful in weight loss as it contains no calories and reduces cravings for sweet and fatty foods. Hunger sensations are reduced when 10 drops Stevia extract are taken before meals. This encourages early satiation and reduced food intake as well as cutting out all those calories usually obtained from sugar.
Does Stevia cause weight gain?
The sweetness of Stevia is due to its ability to stimulate specific taste receptors (T1R2/T1R3) on the tongue even more effectively than sugar. With some artificial sweeteners, increased perception of sweetness can also increase appetite and are not associated with weight loss despite having few, if any, calories. Some artificial sweeteners even appear to promote weight gain by causing sweet cravings so you eat more of other sugary, sweet foods.
Stevia was tested in 30 volunteers who were given a drink sweetened with either Stevia, monk fruit, aspartame or table sugar (sucrose) on four different test days, after a standard breakfast. They were later allowed to eat as much as they wanted from a lunch buffet, and their total calorie intake for the day recorded.
Their average total daily energy intake was 2,241 kcals on the Stevia day, compared with 2,330 kcals on the aspartame day, 2,306 kcals with monk fruit and 2,312 kcals on the sucrose day. The researchers calculated that having a Stevia sweetened drink meant they only ate 73% of their expected calories after having a Stevia sweetened drink, whereas with aspartame they ate 7% more, compared with sucrose.
Another study involving 19 lean people and 12 people whose weights put them in the obese range completed three separate food test days during which they received a snack sweetened with either Stevia, aspartame or sucrose, before their lunch and dinner meal. They recorded their hunger and satiety levels throughout the day, and the amount of food they ate was assessed.
They did not eat more at their lunch and dinner meals after consuming stevia and overall, they ate 301k cals less when having Stevia sweetened snacks compared with the sucrose sweetened snacks. Blood tests showed that Stevia significantly reduced their glucose and insulin levels after eating, compared to sucrose. They also reported similar levels of satiety with Stevia compared to when they consumed a higher calorie sucrose snack.
Stevia and type 2 diabetes
Stevia increases insulin sensitivity and has beneficial effects on blood glucose levels, making it a useful sweetener for people with type 2 diabetes – especially those who want to lose weight. Stevia can be used by people with metabolic syndrome, type 2 diabetes, high blood pressure, raised cholesterol, and may help to reduce the risk of long-term complications associated with these conditions.
Stevia and safety
Extensive safety studies have found no negative effects from using stevia as a sweetener. Stevia is approved for use as a sweetener by the FAO/World Health Organization Expert Committee on Food Additives, and is recognised as safe.