Way too much candy ends up in mishloach manot. Today there is an increased awareness to eating healthy, and many people minimize the unhealthy foods used in mishloach manot preparation. Despite that, just walk into any supermarket in the week leading up to Purim and you will see that many many people still use a lot of junk food in their mishloach manot.

I am not sure this will help much, but Chief Rabbi Yona Metzger publicized a call to people to minimize the inclusion of such foods in mishloach manot and to include more healthy foods instead.
(source: Srugim and Mako)

Rav Metzger said:

Unfortunately in recent years the phenomenon has spread of stressing the beauty and externality of the mishloach manot. This is the opposite of what it should be. Because of that, it is common in many shops, especially in the time of Purim, to find all sorts of sweets that are based on artifical ingredients, containing chemicals, food colorings, things that can cause damage to the body, and especially to children whose body's are not yet strong enough.

Experts in this field have enlightened me that in not so few countries marketing these products has been prohibited, due to their bad influence. These products are sold, usually, at cheap prices, due to low manufacturing costs that do not require a lot of resources. And, there are those who buy them so the package will externally look beautiful and impressive.

The truth of the matter is that we should take care to be concerned that the mishloach manot will not include any such items at all, to pay attention to the ingredients with which the sweets are manufactured, and during Purim when a lot of mishloach manot come into the house the small children could get out of hand eating these sweets and thereby cause damage to their bodies, upon which we have been commanded to protect.

I call with endearment to all our brethren to pay attention to the ingredients of the sweets that are sold in the stores and minimize the mishloach manot that include health damaging products, and by doing this we will merit to fulfill the mitzva of mishloach manot in an elegant way that also has a benefit to the recipient, and will thereby prevent any damage to the health of the recipient and his household.

So, if you have not yet come to this conclusion yourself that you should not be including so much candy and artificial stuff in your mishloach manot, now you have rabbinic counsel informing you of the problem!