Good advice and a lot of people get tripped up by this because yogurt is touted as health food. But most yogurts on the supermarket shelf are no better than a candy bar. Especially since high sugar yogurt is marketed as "low fat" - which is exactly what you want to stay away from when you are losing weight. For fat is often traded off for sugar.
Low fat = high sugar almost every time. And sugar makes you fat, not fat.
The best yogurts to eat are actually those that are high in milkfat - they will have the lowest amount of sugar. Look for the cream topped yogurts too. The ones without the gooey fruit at the bottom.
What I do is buy blueberries or blackberries and mix them in with plain or plain vanilla yogurt with at least 6% milkfat. Brown Cow is a good brand and so is Siggis. In fact, Siggis just came out with a 9% milkfat yogurt (actually called skyr as it is from Iceland).
It would be good to point out that all foods produce an insulin spike. Sugars are BAD, and artificial sweeteners are BAD too! It's best to learn to live without sweeteners. I was using artificial sweeteners in my coffee for years before learning this. Avoiding all of it is best.
Also the raw foods, "as it looks from nature" is a great rule of thumb. Eat that stuff, and you're miles ahead of the curve. I don't call it "paleo" I call it real food.
When coming off a fast, eating fats spike the insulin the least, proteins moreso, and carbs a lot. To keep the weight loss going when not fasting, eat bacon! Avocados! Seriously, fatty foods, moderate protein, and low carbs.
Full fat organic GREEK yogurt is good because of the additional protein too. I mix it with a decent veg juice (not v8) for an easy to drink protein boost. No fruit or sugar.