Why are people talking about Slim Fast? Our attention turned toward ingredients, side effects, clinical research, peer-reviewed studies and customer service quality. Additionally, we dissected hundreds of dieter reviews and comments to see if anyone was successful in reducing caloric intake and weight. Then, we condensed and summarized to give you the information you need.
What is Slim Fast?
First off, Slim Fast is a meal-replacement system offering ready-to-drink shakes, 100-calorie snacks and nutrition bars. The ingredients include amorphophallus konjac , rhizome, apple pectin, oat fiber, fat free milk, water, sugar, gum arabic, canola oil, milk protein concentrate, cellulose gel, coffee powder, mono and diglycerides, potassium phosphate, hydrogenated soybean oil, natural and artificial flavors, maltodextrin, dl-alpha-tocopheryl acetate, phytonadione, thiamine mononitrate , riboflavin, niacinamide, pyridoxine hydrochloride, and folic acid. You’ll replace one meal and incorporate a snack as needed, ideally to curb appetite and keep blood glucose level between meals.
Slim Fast was introduced in 1977. The official website and local grocery stores sell the product line. The longevity of the company and the affordability are positives, but read on…
Poor Taste – “Is it Flavorful?”
The first concern about Slim Fast ingredients was taste. “Meal-replacement shakes , nutrition bars and snacks are intended to substitute regular foods,” said our Research Editor. “If the dieter doesn’t like the flavor, that is more than enough to keep them from sticking with the plan. If you don’t maintain a reduced-calorie diet, you are less likely to shed weight.”
“I purchased Cappuccino Delight. Delightful it’s NOT. The taste reminds me of burnt coffee beans,” said one customer.
“Too much sugar , way too sweet and chocolaty. Does not feel like a meal,” said another user.
On the other hand, we found Slim Fast reviews that didn’t mention poor taste.
“Fills me up and tastes good,” reported a dieter.
Slim Fast Side Effects – “Digestive Issues?”
As we read through more and more reviews, Slim Fast side effects were a concern. “It gave me gas and diarrhea.  Never tried it again,” said a customer.
“The first gave me stomach pain. Within an hour the diarrhea  began again,” said another.
While Slim Fast side effects were a concern for some, others didn’t mention adverse reactions.
“No gastrointestinal issues to speak of,” reported a customer.
“There’s no effects on my digestive system ,” stated another.
Our research has shown that side effects can hamper the ability of a supplement to produce long-term results. If Slimfast causes slight digestive discomfort, a user is unlikely to stick with it.
The Science- “Any Research Behind the Shake?”
Slim Fast does mention some studies relating to its effect on weight-loss. There’s even science-based evidence supporting replacing meals and dieters losing weight. Unfortunately, when we searched PubMed and various medical journals, we were unable to find any peer-reviewed studies to prove it works. It does contain protein and human studies have shown it to “[induce] sustained reductions in appetite.”  We’d like to see a little more soluble fiber, as that ingredient can slow the digestive process. At DietSpotlight, we look for solid science. When there’s no clear link to clinical studies, we become concerned.
The Bottom Line – Does Slim Fast Work?
So, are you heading out to buy a case of Slim Fast? Well, we like the longevity of the company and that it seems affordable, but we’re hesitant about this one because the research doesn’t directly link it to weight-loss, there are no dedicated peer-reviewed studies and elements in the formula that could disrupt / slow the digestive process, like fiber, to reduce hunger and slow the onset of appetite are missing. We’re also concerned about the fact that beverages are not as effective as solid foods in terms of satiety. 
Do you want to trim down a bit? If so, we suggest going with a supplement with no mention of harmful side effects and a formula containing some clinically-tested ingredients shown to help promote weight-loss.
Among the best products we’ve seen in 2016 is one called Leptigen. It features a four clinically-tested ingredients which have been shown to help accelerate metabolism and ignite fat loss. No one’s talking about harmful side effects, but dieters are exited about their great results.
Also, the makers of Leptigen are so confident in their supplement, they’re offering a Special Trial Offer.