Nutrition & Dieting/Nutrition in a pill
The fact that I can take one or more pills to achieve required amounts of nutrition is very appealing as it's easy and much less costly than eating all the different kinds of foods necessary to receive the same nutrition.
Is it possible to achieve a healthy diet by taking appropriate nutritional pills and then utilizing a filling food like bread to complete the diet? I've searched on google but cannot find any studies where they've tested this kind of scenario.
So sorry to take so long. I have not had access to internet for a while due to economic reasons and finally got everything back. I know you've been waiting.
To put a simple answer to your question, it may be an interesting reality, but none the less not an actual one.
A diet is the accumulation of the foods you eat day to day. It needs to be balanced and needs to be energy efficient. Losing, gaining, or maintaining weight is all about energy balance. You input less and expand more to lose, vice versa to gain, and 50/50 to maintain.
Calories are the units of energy you eat. As humans our bodies require certain amounts of energy to operate just like your phone or car or whatever else. That can't be put into a pill form. Also consider that to get enough nutrition needed you'd be taking a truck load of pills each day (well in the multiple hundreds)
Our digestive systems aren't designed for this either. They need to break down whole foods.
Eating just bread as in your example would exclude protein and fat from your diet, both of which are vital. Protein helps to build and maintain muscle tissue. This is vital to prevent degenerative and mobility related diseases.
And in fact many vitamins (A,D,E, & K) are fat soluble, meaning that they require fat to be absorbed into the body.
Now don't get me wrong, I'm a huge supplement fan. I even specialize my study into them. However supplements are effectively a crutch. They "supplement" a balanced diet.
And it should be noted that the vitamins in pill form and those found naturally occurring in food can be from different sources. Each vitamin has one or more chemical compounds that almost mirror its molecular structure. That's how manufacturers get them into pills. They aren't deriving them from plant based sources. Am I boring you yet and getting off task?
the happy medium is with both. Eating 5-6 complete (all macros: protein, fat, carbs) meals daily and taking a multivitamin supplement to support your health.
Contrary to "experts" claims, you can't get all the nutrients you need from whole food. However you really can't get even half from just supplements.