Thank you for asking your query at DoctorSpring.
No diet soda consumption alone is not the cause of this weight gain. The weight gain from diet soda should be minimal as the calories are less in it. A rebound weight gain can be expected even with normal calorie intake in case of rapid weight loss. I would like to know a typical day's diet of yours to comment more. You can reply as a followup. Also (1) do you have any current medical illness (2) What was the surgery done and indication?
Patient replied :
I realize from a calorie standpoint it wouldn't not be responsible for weightgain, but are you of the opinion that aspartame can cause metabolic syndrome or interfere with normal insulin levels, or that the carbonation can cause overall body bloat? No illness currently, I had a hemicolectomy ( 8 inches of dead bowel ) and for no apparent reason. :-)
No there is no evidence to say Aspartame can cause metabolic syndrome or interfere with normal insulin levels or cause any 'significant' changes in body metabolism. There are many claims available online, but they are not backed by solid facts and evidence.
It is true that Aspartame will not result in any major weight loss (if you were taking it for that purpose). But it is unlikely that it will cause any weight gain either. And no way a major weight gain.
Your weight gain is most probably due to body's adaptive response due to the weight loss (negative nitrogen balance to positive). Anabolic steroids in body and hormones play a part in this. Even if you are taking less than normal calories per day.
Hope this helps
Please feel free to ask followup questions.
Patient replied :
Yes, I appreciate your responses and wonder if you would just explain "negative nitrogen balance to positive". I just enjoy knowing how the human body works. After that I shall leave you along about this. :-) Thank you so much!
Please allow me to quote this "Nitrogen Balance = Nitrogen intake - Nitrogen loss
Blood urea nitrogen can be used in estimating nitrogen balance, as can the urea concentration in urine.
A positive value is often found during periods of growth, tissue repair or pregnancy. This means that the intake of nitrogen into the body is greater than the loss of nitrogen from the body, so there is an increase in the total body pool of protein.
A negative value can be associated with burns, fevers, wasting diseases and other serious injuries and during periods of fasting. This means that the amount of nitrogen excreted from the body is greater than the amount of nitrogen ingested. "
-- Now post surgery you have might gone into a kind of positive nitrogen balance. That means body will go into conserving or rebuilding mode. Conserve as much as possible (Nitrogen is mainly derived from protein, but all the nutrients are conserver. Nitrogen is more an index for this)
Simply put your body was able to extract more from the given nutrients. (Ever wonder why some women put on weight post pregnancy even after all the milk feeding and dieting ?- This is the reason).
Hope I am clear.