"Pepsi has the leading market share in the U.S. in sports drinks, ready-to-drink coffee, bottled water, juice drinks, ready-to-drink teas and the number two position in carbonated soft drinks, " notes Stack.

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In order to make low calorie drinks taste better, soft drink makers led by Coke, Pepsi and Dr. Pepper Snapple are experimenting with natural, low calorie sweeteners and flavor enhancers.

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It inspired a number of competitors, particularly as soft drink companies took notice of the demand for drinks with natural ingredients.

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When people drink too many beverages containing added sugar, such as soft drinks, fruit drinks, energy or sports beverages, they tend to put on weight.

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But in the 1980s, carbonated soft drinks overtook tap as the most popular drink, with Coca-Cola and PepsiCo putting their marketing muscle behind their colas with celebrity endorsements from the likes of pop star Michael Jackson and comedian Bill Cosby.

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If you don't want to abstain entirely, there are ways that can help you cut down, including opting for smaller glass sizes, diluting alcohol with soda water or a low-calorie soft drink, alternating between alcoholic and non-alcoholic drinks and keeping a few nights each week booze-free.

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In sum, the small numbers in this study combined with the kind of data collected (limited baseline data, no details of drink ingredient differences) and the narrow demographics do not support the contention that drinking diet soft drinks is going to put you at a risk for a heart attack.

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