如何将选择语句转换为更新语句

Question

如何将此选择语句转换为更新语句？

（目标：计算体重增加）

select we.*,
        we.weight_evening - (select weight_evening
                             from Weight
                             where color = pg.color          
                             and date < we.date             
                             order by we.date desc
                             limit 1                            
                            ) as weight_increasement
from Weight we
where color = "red"