Summary Background Lipid‐lowering effect was observed during treatment with tenofovir disoproxil fumarate (TDF) for chronic hepatitis B (CHB). However, the metabolic features in patients switching from TDF to tenofovir alafenamide (TAF) remain unclear. Aims To compare the impacts of switching from TDF to TAF or from entecavir to TAF on body weight and metabolic features in patients with CHB. Methods This was a multi‐centre, prospective, observational study in patients with CHB on TDF or entecavir who switched to TAF. Baseline characteristics, lipid profile and sugar profile were determined. This study received IRB approval from each hospital. Results We enrolled 177 patients on TDF (99) or entecavir (78) and followed them for 48 weeks after the switch to TAF. At baseline, TDF‐experienced patients had lower serum triglyceride, total cholesterol, high‐density lipoprotein (HDL) cholesterol and low‐density lipoprotein (LDL) cholesterol than entecavir‐experienced patients. The switch from TDF to TAF significantly increased body weight, triglyceride, total cholesterol, HDL, LDL, fasting glucose, glycaemic haemoglobin, insulin and insulin resistance. The switch from entecavir to TAF did not affect these measures. There was no significant difference in atherosclerotic cardiovascular disease risk scores between groups. Conclusions The switch from TDF to TAF was associated with weight gain, derangements of lipid profile, and increased insulin resistance in patients with CHB. Long‐term effects on these metabolic features need further investigation. Body weight increase and metabolic derangements after TDF switch to TAF in patients with chronic hepatitis B.