Frozen dinners are foods that you buy pre-cooked and can eat within minutes of turning your microwave on. The downside is that a factory takes all the power away and does the “cooking” for you.
You do not know what ingredients are used or how clean the “kitchen” is. Processing also involves increasing shelf life which is not always friendly to the food itself. Increasing shelf life is done by heating the food to very high temperatures to kill off any bacterial growth and adding preservatives such as sodium to make sure they do not come back.
A lot of these preservatives are not healthy and taking in too much sodium can cause hypertension. Processing also gets rid of a lot of nutrients such as vitamins, minerals and fiber. The health of a food comes from many areas such as amount and type of calories, nutrients and ingredients.
Most times, these frozen dinners are high in bad calories: saturated fat and simple carbs while low in good calories: unsaturated fat and complex carbs. This adds to the taste but takes away from the health. While they are not the best choice for dinners every night, having them a few times per month (not week) will not kill you, but it will not help you either. Buying fresh ingredients and making your own meals is always the best option.