Eating too much? Too little? How do you know? The labels on food tell you all the goodies, and with some third grade math, you can calculate the per-gram (my favorite) or per-ounce cost and benefit of everything you eat.
Just weigh it. First of all, zero your scale. Most scales will set the zero point based on the Tare Weight, or empty weight.
"the weight of an empty vehicle or container" -- Wiki
From here, add your food items one at a time, and if you have trouble calculating the individual items from the whole weight, just reset the zero point on your scale between items.
Studies have shown that even practicing professional nutritionists don't accurately calculate their caloric and macronutrient intake on a daily basis. This way you can say for certainty that you know what you're eating and with good journaling, can determine the effects on your progress.
If you can't measure it, you can't manage it.