I began using Metamucil (or generic brands) after I read that having a glass of metamucil 15 minutes before eating would reduce the impact on blood sugar. My doctor had diagnosed me with Type 2 diabetes and I wanted to pull my blood sugar under control. As I worked at bringing my blood sugar under control I discovered that my fasting blood sugar when I first wake up was typically higher than my blood sugar about 4 hours after I ate and before I went to bed.
Because I research the crap out of everything I am interested in I spent some time researching fiber (or fibre), particularly at www.nih.gov.
Anecdotally fiber makes me feel fuller. If I drink a metamucil and then drink a protein drink I feel full. The blood sugar impact of the protein drink is lower. In my opinion this means that the metamucil slows the digestion of the protein drink.
This is a good thing and a bad thing. Right before and right after a weight lifting workout you probably want to digest protein as fast as possible. Liquid proteins digest faster than solids, BUT, there is also a lower percentage of the available protein digested.
Newsflash, not every calorie in every bit of food that you eat is properly digested and used. Some calories pass right through your system (everyone who has had diarrhea knows this). Taking some kinds of laxatives can cause your digestive system to speed up and reduce the absorption of calories from your food. Some laxatives can slow down food processing which can help regulate your system. Weight loss surgery and useful weight loss drugs typically reduces the time food spends digesting and being absorbed into the system
Different kinds of foods digest at different speeds. After a lot of research I have come up with a guideline I use for eating. Most refined carbohydrates usually digest quickly and are absorbed easily. Fats digest slowly and easily. Proteins digest moderately and are difficult to adsorb. This probably sounds pretty easy to find out, but, verifying this information with actual scientific studies can be difficult. As always I suggest you do your own research, my two favorite places for diet research are Cancer.gov and NIH.gov.
Aside from just before and just after a weight lifting workout when you want to absorb protein as quickly as possible I believe Metamucil is a useful tool to help your system absorb protein. By drinking a metamucil before drinking a protein drink you can cause your digestive metabolism to slow and probably absorb more of the available protein in the drink.
This is also true for solid proteins like Tuna which we all know and love so very much. I like a little hot sauce with my canned tuna, although I eat it just as it comes out of the can quite often. I drink a metamucil before I begin prep, about 5 minutes before eating, and I believe that it slows down my digestion and helps my system absorb protein.
There are also some supplements that help reduce the absorption of some carbohydrates, L-arabinose is one of them. In August 2007 the international journal of Medical Sciences published a paper by Dr. Harry G. Pruess of the Georgetown University Medical Center that found L-Arabinose pretty much eliminated the effects of sucrose on blood sugar. Does this mean your system will not absorb the carbs? I doubt that, I believe that Advocare's Carb-Ease will reduce the glycemic effect. Dr. Pruess's paper does not specifically address weight gain or loss. Advocare funded the study so you have to look for the information that isn't there are well as the information that is there.
In my opinion, if you manage the absorption of calories you consume as well as the amount of calories you consume you can reduce your feelings of hunger, the impact of what you eat on your system and your metabolism.