It's simple. Eat less, breathe more. We store fat as chains of carbon, your blood stores sugar as glucose, when we pack in our muscle it's stored as muscle glycogen, too much is stored as fat. You've got train hard to build or preserve muscle mass and burn the glycogen.
Nutrition is also king, it's only so much exercising can provide you in fat loss. A bad diet will beat you training regime 9/10. Some studies have suggested our bodies even conserves energy output and down regulate energy expenditure throughout the day.
But you need to be patient assuming your 20+ lbs overweight.
1. Eat at a caloric deficit of 10-15% (use a TDEE calculator . Net to determine your caloric range, select sedentary)
2. Track your calories. Aim for something like 35% protein. 35% carb, 30% fat. It's about calories in and calories out. But don't get it twisted calorie quality matters.
Calories in your food are different then the calories in your gut. Foods high in fiber and protein that are complex in digestion process like chicken and leafy greens requires lots of energy to breakdown and digest and these types of foods have calories that contain non-digestible fiber which means the amount of calories you intake will naturally be lower than the on the label. So look to consume high protein, high fiber foods (chicken, kale, greens broccoli, berries, oatmeals, black beans). These foods will also create more satiety. Eliminate liquid calories. 300g of veggies daily, 200g of fruit daily
3. Pick an exercise you like and can stick to and do it.. The exercise itself doesn't matter, it matters about the way you do it. (How often, how intense, etc). The more exercise variety the better.
4. 300 mins weekly (150 mins each) weight lifting and cardio
5. Enjoy food and social life. Don't go cold turkey unless you built for it, otherwise, we'll see this thread again in the future.