I agree with what Sarah And Robert E had to say. In particular the part about soda and sugary drinks. In my opinion, kids don't need to be drinking sodas as anything more than an occasional treat (when she's a guest at a party when it is all that is offered perhaps..). Milk is ok (barring sensitivities) even though it also has sugar, but it contains proteins and fats that are filling, so kids are not as likely to overindulge like they would with soda. And it doesn't contain the phosphorous that is bad for their teeth like carbonated drinks do.
Same goes for a lot of juice. Kids don't need that. They can get their Vitamin C from eating actual fruit.
You didn't mention if this is typical for your daughter's growth patterns (to have a bit of a tummy from time to time). I know when my daughter was younger, there was a definitive period of time every year (usually at the beginning of summer) when she would get rounder and then grow up and thin out. Every year. Same thing.
Does your daughter do that?
Kids have a tendency to go rounder as they go into puberty as well (not just girls, boys do it, too... for about 2 years from what I have observed), but your daughter should not be hitting that pre-pubescent stage just yet. Not at 7. Most girls (not all, but most) hit that closer to age 10/11.
Observe her diet and make small adjustments if needed. Not necessarily calories, or quantity, but quality. Grilled instead of fried. Chicken nuggets made at home from chicken breasts cut up and baked in your oven vs. McDonald's drive-thru. Fruits and veggies (whole pieces, not juice) instead of mac and cheese and french fries.
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ETA
And from what I just looked at on a growth chart, for her age, she is in approximately the 25th percentile for height, and the 90th percentile for weight. Those numbers are pretty far out of proportion. She's shorter than 75% of kids her age, and heavier than 90% of kids her age. So yeah... that's heavy. And according to a BMI chart, almost obese (high end of "overweight"). http://kidshealth.org/parent/growth/growth/bmi_charts.htm...
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Regarding the granola type bars. Read the labels. Most of those are not as nutritious and healthy as they advertise. Compare the amount of sugars and carbohydrates (carbohydrates convert to sugar in the body) and fats to the amount of protein in them. Most of those bars are almost ALL carbohydrates. Which is fine if she is a distance runner prepping for a half-marathon. Not so much if she is just an average kiddo.
They aren't harmful, but she'd be better off eating a handful of nuts (walnuts, peanuts, almonds) which contain protein and good satiating fats, minus all the carbs (read "sugar" whenever you see carbs on anything that isn't a vegetable). Or eating a piece of whole fruit. Apples, grapes, berries. Cliff bars have a HUGE amount of calories. Read the labels and really consider how many calories are in those things compared to the amount of calories a healthy diet for a 7 year old should contain.
I just pulled a Clif bar out of my pantry to see (my 16 year old wrestles and takes weight training (daily)) and he will sometimes eat these... 240 calories. 44 grams of carbs. This is not a "snack" for a 7 year old. It might be half of a lunch.... but not a snack.
Try a piece of string cheese, a handful of almonds, and a big glass of water or some popcorn (they sell microwave popcorn in small single size portions that are 100 calories each). The popcorn has fiber, takes a while to eat and has lots of "crunch value" (meaning your mouth works a lot to eat it so it is satisfying from the mental side of things).
If she doesn't like veggies at all, what does she eat with her meals? A meat and _______? Does she fill up on bread or pasta or rice instead? Carbs and mostly empty calories. And usually are topped with fattening choices like butter, sour cream or sauces and gravies.
Do not make a big deal about this in front of your child. Don't. Just start gradually changing what is available and what is offered to her. Be a good example of how and what to eat, also.
Does she take her lunch to school? What's in it? Or does she eat the school lunch? Have you looked at a typical school lunch lately? She's probably better served eating a PB&J sandwich on whole wheat bread, an apple, and a handful of popcorn or a cheese stick. Bottle of water to drink.