Rather than respond to individual posts, I'm going to attempt a rather broad discussion on carbohydrates, sugars, and dieting. My personal pet peeve as a doctor is anti-carb sentiment and the Atkin's diet philosophy that carbohydrates and starches are inherently the root cause of all people being overweight. It is a very simple equation, calories in should equal calories out. If you eat and balance your calorie intake to your calorie expendature you will maintain your weight. If you eat more calories than you require you will gain weight. It does matter to some degree what type of calories you ingest, but the total quantity is overall more important.
Every Olympics they like to run segments on what and how much the Olympic athletes eat. When they looked at Michael Phelps he was consuming an almost obscene amount of calories, including those bad starchy carbs. He would eat pancakes, pizza, bread, and even candy. I'm not sure exactly how many calories, but I think the total was over 4,000 cal/day. Us mere mortals would balloon to morbidly obese in a very short time eating that many calories.
I have the children's riddle, what weighs more? a pound of feathers or a pound of bricks? They are actually the same, one pound. However, the volume of feathers vs the volume of bricks is very different. You would fill up well before 500 calories trying to eat celery or cucumbers. You could get to 1,000 calories with most restaurant desserts. I feel it is important to focus not on the sugar or carbohydrate but the total number of calories. Take a 12 oz. Coke for example, it is about 140 calories. One Coke a day could lead to 10 lbs weight gain over 3 months. Don't drink sodas? Keep in mind one breadstick at the Olive Garden is about 160-180 calories each. That's more calories than a can of Coke.
If you took a piece of paper and a pencil and drew a diagram of a glucose molecule you can't tell what source it came from. Glucose is glucose. But, how concentrated foods are varies greatly. Fresh fruits and vegetables have some, concentrated sugars have a lot more in a very small package. It is more the concentration of glucose/sugar that is the problem.
The Glycemic Index was mentioned, but a better and more accurate measure of carbohydrates is the Glycemic Load - in otherwords, how much volume did you have to eat to get to the glycemic load. Watermelon may be a little high on the Glycemic Index but the Glycemic Load is very low. It actually has less sugars and carbohydrates since the majority of the fruit is water compared to what the Index may seem to imply. A French baguette however is very high on both the Glycemic Index and the Glycemic Load. If you are going to eat, then eat in moderation.
Which is actually the main point. Everything in moderation and nothing to excess. The carbohydrates aren't necessarily bad, but the amount of calories in sugars and carbs can be overwhelming in very small amounts. It can fool you if you eat by visual guestamations of volume. You don't think you are getting as many calories in the smaller volumes but you may be shocked when you start counting. By default, since fresh fruits and vegetable in particular have much fewer calories by volume they should be the preferred choices.
I've seen the studies on Anti-Aging, have even attended some of their educational conferences. I personally found them to be a little more gimicky and hype than actual medical science. Just my interperetation on what was being presented. You also have to be very careful about what is being presented as science. I had one personal trainer tell me that if you fast you will become obese. He was mistakenly trying to tell me that fasting creates high levels of insulin to be secreted by the body. Actual medical fact and phsyiology is that fasting decreases insulin production. And it is not an issue with glycemic spikes and insulin release, it is the amount of adipose and fat tissue that has to respond to the insulin. Obese weight and increased BMI is the concern for insulin resistance and pre-diabetes.
Eat in moderation, exercise, maintain lean body weight and you won't have to worry as much about what you eat. Then again, if you have a lean body weight to begin with you must be doing something right.
Sorry if it is a little long.