Alternatives for 'eval' command?

Hello. I've discovered eval command to solve some of my problems. But also I've just read that's inefficient and threaten (!del *.m") too. Any suggestion to improve my code? It's like this example, where I want to apply some algebra/functions to different fields (names_2) of main variables (names_1), which are structures. Thanks in advance.

Var_1.cast1=rand(5,10);Var_1.cast2=rand(7,20);Var_1.cast3=rand(4,8); Var_2.cast1=rand(3,10);Var_2.cast2=rand(9,20);Var_2.cast3=rand(6,8);

for k=1:2

    names_1{k}=strcat('Var_',num2str(k));
end
for k=1:3
    names_2{k}=strcat('cast',num2str(k));
end

for k=1:length(names_1)

    v=genvarname(names_1{k});
    for i=1:length(names_2)
        aux_var=eval([v '.(names_2{i});']);
        aux_var_2.(names_2{i})=aux_var(:,2:end)';
    end
       eval([v '=aux_var_2;'])
       clear v aux_var aux_var_2
end