What is more beneficial for body fat loss in terms of food & type of exercise?

Simply if I had only 1 hour a week to fit in exercise I would be weight training. Weight training is the foundation to body fat loss. Simple more muscle equals more energy burnt during exercise and normal daily life. Weight training will help to raise the metabolism. It will also help to maintain your muscle mass instead of if you were to just to cardio then you would more than likely lose your muscle mass, decreasing your metabolism. Also if you make your muscle mass less then you will make your storage of carbohydrate smaller increasing the chance of actually putting on fat.

Then which cardio is more beneficial to losing body fat - hard vs low to moderate?

First we must understand how we use macronutrient to produce energy. Glucose is used to produce energy (ATP). Therefore glucose is our primary source of energy. Therefore, carbohydrate is a much faster and easier source to produce energy. Whereas fat must be broken down to glucose and then glucose is used to produce energy. With this understanding, we must also understand that we also use these macro nutrients in ratio to each other according to intensity. As intensity is increased then the ratio moves towards carbohydrate compared to fat, as glucose is faster to use. As intensity decreases though, the ratio switches to more fat being use as opposed to carbohydrate. And as time progresses the usage of fat increases too. Therefore, we should do both low to moderate and hard cardio to lose weight and be able to maintain it for the rest of your life.

More specifically we must also consider your body type. Your body type will determine what ratio of hard vs low to moderate cardio exercise you should perform. There are 3 different body types; Ectomorph, Mesomorph and Endomorph. Mesomorphs will lose body fat with hard interval training as well as some low to mod. Hard interval training can aid in maintaining if not growing muscle mass too - have a look at sprinters body's vs long distance runners. Endomorphs will lose more body fat with more low to mod compared to hard.

In terms of eating, look for wholesome, low GI, fibrous, nutrient dense foods. Foods that nourish and actually aid in gut health. As much as we need to consider the energy intake to achieve your weight loss and fitness goals, we also need to make sure you eating the micro nutrients. It is actually the minerals and vitamins that are helping your body feel good, have energy and reduce sickness. Minerals and vitamins are crucial for your body. Without these, you will be prone to sickness, less energy, less focus, and an increased stress load. Foods that are less processed will have an abundance of these minerals and vitamins. Lastly consider foods you like to eat as well. If you are going to make a habit of this for the rest of your life, finds foods that you enjoy to make and eat.