Almost all of them? Well, let's put that claim to the test.
In Game & Watch Gallery, two of the four games include Yoshi in some capacity.
The games in question are Manhole and Fire.
Neither of the games involve him eating, though he does use his tongue to position the lower manholes
In Game & Watch Gallery 2, four of the six games include Yoshi in some capacity.
The games in question are Parachute, Chef, Vermin and Ball.
Only one of them involves him eating, Chef.
In Game & Watch Gallery 3, two of the ten games involve Yoshi in some capacity (as far as I know). This is the one I'm least clear on because it's the only one of the original Game & Watch galleries I haven't played, he might also appear in one of the other games.
Either way, the two games in question are Egg and Greenhouse.
Both games involve Yoshi eating, Cookies in Egg and Watermelons in Greenhouse.
In Game & Watch Gallery 4, only 11 of the 20 playable games can be played with Mario characters. 4 of those games include Yoshi.
The four games in question are Fire, Rain Shower, Mario's Cement Factory and Chef.
Only two of the games involve Yoshi eating, Mario's Cement Factory and Chef.