By the time you're 30 and ideally well before, you should be in the habit of always checking food labels before buying. This way, you can avoid any unpleasant surprises in the ingredient department and can monitor your nutrient intake better. You might think the frozen meal labeled "organic" is healthy for you, but then you check the sodium amount, and it's nearly half your day's recommended intake. Know what you're eating, and stick to natural foods as much as possible.