Like so many other people, I'm just a little bit overweight — something that's come naturally with age and a love of good food. I've done stuff to try to shed the extra pounds, on and off (see healthy vegetarian weight loss for total noobs, for instance), but I usually revert to the weight that is now seemingly natural for my body given my unwillingness to stop eating stuff I enjoy in the quantities I want.
When the friend who set me up with kefir grains and explained how to use kefir grains to make kefir at home introduced me to the tasty probiotic drink, she immediately identified it as the sole cause of her rather impressive recent weight loss. Nope, she said, she hadn't made any other nutritional or lifestyle changes and yes, her waistline had definitely shrunk. A lot. If it worked for her, I was certainly willing to try it too. And yes, I've had some results — I lost about two kilos since I started drinking kefir about a month back. Not as much as my friend, but still not nothing.
Do Any Studies Show That Drinking Kefir Leads To Weight Loss?
If you go looking for studies about kefir-related weight loss specifically, you'll find just the one that examined whether two servings of kefir a day would help a group of overweight and obese premenopausal women lose weight. Its authors separated their study subjects into three groups, the two non-kefir ones either drinking two servings of low-fat milk or just keeping their diet the same (AKA the control group). Women in the milk and kefir groups both lost comparable amounts of weight after eight weeks, while the control group obviously didn't. 
Though there's a clear lack of studies that clearly show that kefir can cause you to lose weight, the research doesn't end there — we just have to look at whether the things you'll find in a cup of kefir can help you lose weight. Science delivers on this count, and we'll take a look at that now.
Both milk and kefir contain something that countless people who are trying to lose weight overlook — dietary calcium. While a calcium deficiency is associated with weight gain, an increase in your calcium intake is linked to weight loss. More specifically, increased calcium consumption promotes fat loss. [2, 3] (That's one reason folks about to undergo a gastric bypass are put on a nearly all-milk diet, yes?)
While kefir contains things milk doesn't (more about that in a bit), its nutritional composition is incredibly similar. You'll find about eight grams of protein in a single glass of milk , and getting enough protein can help you feel fuller for longer, improve your metabolism, and thus cause weight loss .
Each "colony" of home-grown kefir grains varies in its probiotic composition, but various species of Lactobacillus (or lactic acid bacteria) are always an essential component, certainly one of the reasons for which drinking kefir has been shown to be extremely beneficial to gut health . Lactobacillus supplements hold great potential in helping obese people lose weight , again because it aids gastrointestinal health by altering your internal microbiome for the better.
My Personal Experience
I'm no calorie-counter, but I don't need to be one to realize that the kefir I drink contains many fewer calories than the carby nonsense I turned to for breakfast before I started making kefir with kefir grains. As someone who, like, really enjoys food, I can say that a large cup of kefir makes me feel full and satisfied for hours — and while I'm feeling that way, I'm not eating anything. I figure kefir is better than plain old milk because of the stronger probiotic content as well as the better taste.
Drinking kefir every day may well help you lose weight, too, especially if it leads to a reduction in your daily calorie intake, but it will certainly be good for your overall health — kefir has been proven to aid digestive health, reduce cholesterol levels, strengthen your immune system, and it has anti-tumor properties as a bonus . It's not for nothing that the Turkish word "kefir" was derived from means "feel good". The best weight loss is that which focuses on overall health and nutrition, rather than just the number on the scales, and drinking kefir is a wonderful step in that direction.