Lots of miles at a moderate pace works best. To many hard miles and you will likely hunger more than you need causing you to out eat your riding. 1 mile running ~= 4-5 miles on the bike. I had the best weight loss when I was riding every day, several times a day. Some days a morning commute 3.25 miles at the time, short lunch time ride and then a longer after work commute, often 12+ miles. Then on weekends longer rides 30-70 miles. All the while paying attention to what I was eating. Salads for lunches during the work week. Weekend rides were done through lunch time so if I ate it was about 200 calories per hour on the bike nutrition. Eggs nearly every morning for breakfast. Meat for dinners with veggies but not lots of carbs. Once or twice a week we did eat spaghetti. Other exception to that was tortillas when we had tacos or fajitas. Stayed away from bread at lunch and dinner and limited potatoes.
What will work for you might be a far cry from what worked for me. How much time are you willing to commit to riding in an effort to lose weight? 125 miles a week along with eating to lose weight should get you there.
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Sir Mark, Knight of Sufferlandria