There is nothing particular that you can eat to widen your hips. If you eat a lot of food without doing enough exercise you could gain weight on your hips, but it could just as easily go onto your thighs, arms, buttocks, anywhere really. If you want your hips to seem bigger try getting a 'waist belt' (a smaller, thicker belt designed to give the appearance of a smaller waist). Pulling in your waist a little with one of these will make your hips look wider, giving you a more 'hourglass' look.
I'm a personal trainer. My advice is to lift weights and do strength exercises, like squats and calf lifts. When lifting, I recommend you do one repetition with the most weight you can handle, and repeat for four-five sets. You can also do 8-20 reps at a lower weight, also for four-five sets. As you gain strength, gradually increase your reps to sets of 10, but at the beginning the point is simply to improve your strength.
As far as diet goes, eat a little bit of everything, but mostly focus on carbs. Since carbs can increase fat, do some abdominal crunches, but keep cardio to a minimum because it will be harder to increase muscle mass if you're running a lot.
As far as diet goes, eat a little bit of everything, but mostly focus on carbs. Since carbs can increase fat, do some abdominal crunches, but keep cardio to a minimum because it will be harder to increase muscle mass if you're running a lot.