Why diet soft drink or soda might not help you lose weight
Posted Jun 14 2013 10:00am
When you’re trying to lose weight, you may have deliberately chosen ‘diet’ soft drinks instead of the sugar-laced variety. Fewer calories going in should result in weight loss, surely? Unfortunately, scientific research suggests that choosing artificial sweeteners, especially in soft drinks, could have the reverse effect: weight increase. They suggest a different approach.
It doesn’t seem logical, that choosing diet soft drink could make you gain weight; but your body’s biochemistry is actually effectively fooled by the sweet taste. Although the artificial sweetener doesn’t contain any calories, your body is likely to behave as if you had actually eaten real sugar, responding with insulin secretion, promoting fat deposits, that sort of thing. It turns out that our cells don’t just respond to what’s actually happening, but to what they believe is happening, whether it’s true or not.
A sweet taste to what you eat (real or artificial) has been shown to influence the type of food you’re likely to prefer next time. That means that if the foods in your diet have a predominately sweet taste, you’ll be drawn more towards eating sweeter tasting foods. The reverse is also likely: If you train your palate away from sweet tastes, it’s easier to avoid sweet food. This may be why diet soft drink doesn’t have an impact on weight loss – because it doesn’t change the underlying desire for sweetness. Keep in mind that this phenomenon applies to ‘natural’ sugar substitutes like stevia too. You’re not likely to ever completely lose the attraction to sweet tastes, that’s a natural human predilection, but you can certainly manage the desire.
The best article I’ve come across so far for explaining why artificial sweeteners don’t really help weight loss was published in the June 2010 edition of the Yale Journal of Biology and Medicine, page 101-108 . The full article can easily be accessed through Google Scholar, and is easy to read. (Tip: Download the PDF version for more comfortable reading, and ignore the technical-looking molecule charts unless that’s your thing.)
If you want to get healthier and lose weight by eating less sugar, science suggests that you need to re-train your flavour preferences, not switch to the artificially sweetened substitute. If you’re already strongly attached to sweet food, like soft drinks, the easiest way to cut down is gradually; look at how much you drink now, and cut it down by a quarter. Replace the soft drinks with filtered water flavoured with a squeeze of lemon or lime juice. Next week, cut down more. Once you’ve conquered your soft drink consumption, start reducing your intake of other sweet tasting foods. Before you know it you won’t feel the same craving for a sweet foods or drinks, and you might notice the difference in your waistline too.