There’s a related thread about water here in GQ. Here’s one of my replies:
Note that altho Web MD is not a bad source at all, they still pick and choose amoung articles, often seeming to choose those which support their agenda.
For example, here’s a AJCN article
http://www.ajcn.org/content/76/4/721.short
"*Background: The role of artificial sweeteners in body-weight regulation is still unclear.
Objective: We investigated the effect of long-term supplementation with drinks and foods containing either sucrose or artificial sweeteners on ad libitum food intake and body weight in overweight subjects. …
Results: After 10 wk, the sucrose group had increases in total energy (by 1.6 MJ/d), sucrose (to 28% of energy), and carbohydrate intakes and decreases in fat and protein intakes. The sweetener group had small but significant decreases in sucrose intake and energy density. Body weight and fat mass increased in the sucrose group (by 1.6 and 1.3 kg, respectively) and decreased in the sweetener group (by 1.0 and 0.3 kg, respectively); the between-group differences were significant at P < 0.001 (body weight) and P < 0.01 (fat mass). Systolic and diastolic blood pressure increased in the sucrose group (by 3.8 and 4.1 mm Hg, respectively) and decreased in the sweetener group (by 3.1 and 1.2 mm Hg, respectively).
Conclusions: Overweight subjects who consumed fairly large amounts of sucrose (28% of energy), mostly as beverages, had increased energy intake, body weight, fat mass, and blood pressure after 10 wk. These effects were not observed in a similar group of subjects who consumed artificial sweeteners. *"
and another:
http://www.ajcn.org/content/51/6/963.short
“To examine whether artificial sweeteners aid in the control of long- term food intake and body weight, we gave free-living, normal-weight subjects 1150 g soda sweetened with aspartame (APM) or high-fructose corn syrup (HFCS) per day. Relative to when no soda was given, drinking APM-sweetened soda for 3 wk significantly reduced calorie intake of both females (n = 9) and males (n = 21) and decreased the body weight of males but not of females. However, drinking HFCS-sweetened soda for 3 wk significantly increased the calorie intake and body weight of both sexes. Ingesting either type of soda reduced intake of sugar from the diet without affecting intake of other nutrients. Drinking large volumes of APM-sweetened soda, in contrast to drinking HFCS-sweetened soda, reduces sugar intake and thus may facilitate the control of calorie intake and body weight”
and another:
http://www.ajcn.org/content/84/2/274.short
Consumption of sugar-sweetened beverages (SSBs), particularly carbonated soft drinks, may be a key contributor to the epidemic of overweight and obesity, by virtue of these beverages’ high added sugar content, low satiety, and incomplete compensation for total energy. Whether an association exists between SSB intake and weight gain is unclear. We searched English-language MEDLINE publications from 1966 through May 2005 for cross-sectional, prospective cohort, and experimental studies of the relation between SSBs and the risk of weight gain (ie, overweight, obesity, or both). Thirty publications (15 cross-sectional, 10 prospective, and 5 experimental) were selected on the basis of relevance and quality of design and methods. Findings from large cross-sectional studies, in conjunction with those from well-powered prospective cohort studies with long periods of follow-up, show a positive association between greater intakes of SSBs and weight gain and obesity in both children and adults. Findings from short-term feeding trials in adults also support an induction of positive energy balance and weight gain by intake of sugar-sweetened sodas, but these trials are few… The weight of epidemiologic and experimental evidence indicates that a greater consumption of SSBs is associated with weight gain and obesity. Although more research is needed, sufficient evidence exists for public health strategies to discourage consumption of sugary drinks as part of a healthy lifestyle.
But yes, there is also some evidence that diet drinks don’t help with weight loss. However not helping with weight loss is different than “There is no solid evidence that diet beverages have any bad health issues.”
Thus the evidence seem to be that drinking diet beverages is generally safe. They are also hwaaaay less fattening than sugar or HFCS beverages. But, do not think that just switching to diet soda alone will nessesarily result in a weight loss.