This topic could fill library after library with tedious details, so I'll keep it as short and as simple as I can. We all eat food, some of us love meat, some of us love heavy carbohydrates, others love more of a plant based diet, but what our bodies do with that food is very similar in the big picture. How you may feel after certain foods however, may make us feel and perform quite differently.
Sluggish, tired, unmotivated people more than likely are missing something in their diets and/or sleeping patterns. Small levels of dehydration can wreack havoc on our bodies. The same havoc can be thrown our way when we don't eat the right amount of nutrients, minerals, fats, carbs and proteins.
Eat a Bagel (or a waffle, or an apple, or a protein bar): Your body will immediately do its best to turn that food into energy (Sugar AKA Glucose)
Your body breaks down the food you've eaten and your blood sugar levels rise. Certain foods make these jumps in blood sugar higher and faster than others. Foods higher in protein (and fat) will help rebuild and repair muscle tissue and can slow this jump down.
The pancreas, detecting that rise in sugar in the blood sends a signal to send out Insulin to allow the sugar entry into your cells to be used as energy.
If there's a malfunction with the Insulin/Blood Sugar exchange, your blood sugar will be High / This can lead to Diabetes over time. So can years of constant Blood Sugar/Insulin jumps and drops, jumps and drops...
Your body (especially the brain) needs sugar constantly or you will die / After the body has enough sugar and the cells are full, the body stores the extra in your Muscles and Liver. This stored sugar is called Glycogen.
This is used when you're in between meals (if needed), training at a pretty high intensity, and when you're sleeping.
If you consume too much food and the bodies cells are full and so are its glycogen stores, the body has to do something with the excess sugar, so it stores it as fat in your fat cells.
You're born with a certain amount of fat cells / If you gain weight and become obese your bodies fat cells actually multiple to handle the overflow of food.
Now say you're heavy and lose weight, guess what happens to those extra fat cells? They shrink, but still remain! Meaning you're at a higher risk of becoming fat again later down the line. This doesn't mean that you will, but the risk is higher for you.
That doesn't mean give up trying to get lean, that means with the proper life style changes, you can become lean and stay lean forever.
Eating foods in moderation and smaller amounts will help prevent those high blood sugar and insulin spikes. Eating more protein, fruits and vegetables will also help. Eating doughy, fried foods in large quantities will make you sluggish and will pack on the pounds quickly, we all know this, but sometimes hearing it will help us make smarter choices.
Your daily diet should consist of MODERATION, not DEPRIVATION! Yes, you can (and should) indulge sometimes, even daily can be ok depending on what it is you're eating and how much of it. If you have a 5 pound fat loss goal you may be able to indulge a little more than a person with a 50+ pound fat loss goal.
No foods are necessarily "bad" for you...It really is just one factor that plays a role with dozens of others. Your daily activity level, your quantity of food eaten, your quality of food eaten, your sleep patterns, your stress levels, your sex life, your water intake, the people you hang out with, your alcohol consumption and the list can go on.
I hope you enjoyed this little breakdown - You all KNOW what to do, the trick is just doing it!