It is not that I cannot eat on Vyvanse. I just do not want sugar the way I used to. Is that normal?

Not wanting sugar the way you used to on Vyvanse can happen, and decreased appetite is a common labelled effect, but that does not mean every person must lose sugar craving, and normal is not a single official target. Health Canada's Vyvanse (lisdexamfetamine) product monograph reports that about a third of trial participants had decreased appetite, and anorexia is also listed. Official language is decreased appetite or anorexia, not a proven change in reward wanting, and the exact reason a sweet tooth fades for one person and not another is not fully understood. If the change is persistent, distressing, or affecting daily functioning, bring a brief timeline to the prescribing clinician rather than changing the dose independently. References: https://pdf.hres.ca/dpd_pm/00084946.PDF https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=704e4378-ca83-445c-8b45-3cfa51c1ecad https://www.nice.org.uk/guidance/ng87/chapter/recommendations https://www.nhs.uk/medicines/methylphenidate-adults/side-effects-of-methylphenidate-for-adults/