Scripture teaches us that God declared all foods clean through Peter's revelation...in fact God told Peter to get up and eat foods that in the past Peter would have been condemned for eating. I often think of this section of scripture when I'm considering eating foods that are full of nitrates and refined sugar and highly processed "foods". I'm really not sure that these were the things that God declared clean. He was specifically referring to certain types of animals that in the past were considered unclean.
To say that all foods are good and can be consumed in moderation is a stretch. Truth be told, there are products that we eat that simply are not natural. They are man made, chemically based products, formed to resemble food items. They may even in fact contain some natural food ingredients, but by and large, are not "created by God". Common sense tells me that Ring Dings and Twinkies didn't grow out of the ground, nor were they raised on a farm for sale later at the food market. They are comprised of chemicals created in labs (kitchens??) by man to entertain our fast and easy, sweet tooth based lifestyles.
I'm not condeming any and all consumption of these products. What I am focusing on here is the fact that moderation may even be too much. Moderation would imply regular, yet slow in pace consumption. Occasional might be a better train of thought.
Look around at the chronic dilemma facing us today in the US. Obesity, diabetes, high blood pressure, neurological disorders...why are these problems (and many more) so rampant? Why do we now have to have a National Health Plan where folks have to be told what you should and should not eat? Because of the foods we eat. Because we package chemicals and fats and sugars and call them "snacks" or even "meals" and it becomes a way of life.
Eat God's food first. Simply put: If it didn't grow out of the ground, or have to be fed...it's not God's food. God has provided the best foods in his own pantry. He knows what we need to live out our purposes. Remember how he provided manna for the Israelites? It was all they needed...it was His food.