Will I Have Quick Weight Loss on The Slim Fast Diet?


question-icon-newI would like to know what would be the fastest way to lose weight using the Slim Fast diet? Also, is Slim Fast the best way to go for losing weight? If not, what do you recommend? I would like to lose 15 pounds in the next 2 months.

answer-icon-newSlim Fast comes in a variety of different shake flavors, bars, snacks and pre-mixed shakes. Here are the ingredients in a Slim Fast pre-packaged shake:

INGREDIENTSFat Free Milk, Sugar, Cocoa (Processed With Alkali), Canola Oil, Fructose, Calcium Caseinate, Gum Arabic, Cellulose Gel, Hydrogenated Soybean Oil, Mono and Diglycerides, Potassium Phosphate, Soybean Lecithin, Cellulose Gum, Carrageenan, Isolated Soy Protein, Artificial Flavor, Maltodextrin, Sucralose and Acesulfame (Nonnutritive Sweeteners), Dextrose, Potassium Carrageenan, Citric Acid and Sodium Citrate. Vitamins and Minerals: Magnesium Phosphate, Calcium Phosphate, Sodium Ascorbate, Vitamin E Acetate, Zinc Gluconate, Ferric Orthophosphate, Niacinamide, Calcium Pantothenate, Manganese Sulfate, Vitamin A Palmitate, Pyridoxine Hydrochloride, Riboflavin, Thiamin Mononitrate, Folic Acid, Chromium Chloride, Biotin, Sodium Molybdate, Potassium Iodide, Phylloquinone (Vitamin K1), Sodium Selenite, Cyanocobalamin (Vitamin B12) and Cholecalciferol (Vitamin D3).

Aside from the other 42 chemically derived additives which would need an entirely separate article to be addressed, let’s start with the 4 real ingredients in Slim Fast. We have (essentially) skim milk, sugar, cocoa, and canola oil. All other ingredients on this list are just additives. Please note that additives turn toxic in the body, which also keeps fat on the body.

Since most of this product is very high in sugar and full of processed ingredients, it does not make it a very good candidate for a weight loss product. Let’s address what goes on in your body when you ingest a high sugar product. I do realize that the first ingredient listed here is a nonfat milk product which could ideally serve as a bit of a buffer to the bloodstream, but not enough in this case. Sugar is the 2nd and 5th ingredients. That’s quite a bit of sugar to the gut all at once!

Every time you consume sugar (especially by itself) you are training your body to “lock in” and store body fat.

insulin-glucagon-functionYou have two important hormones that play a role in fat release in your body, insulin and glucagon. You’ve probably heard of insulin in relation to diabetes as diabetes is a blood sugar irregularity and insulin is the hormone that regulates sugar transport storage.

When you eat the “good sugars” (a.k.a. complex carbohydrates, like whole grain breads, whole grain pastas, oatmeal, potatoes, yams, etc.), you have consumed long chains of sugars that are linked together. These long chains of sugars are the reason these carbohydrates are termed “complex carbohydrates”. When complex carbohydrates pass through your digestive tract these chains are slowly broken apart sending a slow trickle of sugar into the bloodstream. Take note that fibrous carbohydrates cause virtually no spike in your insulin sugar level.

Glucagon is an energy releasing hormone. It’s job is to free up body fat for you to burn as fuel. The job of the pancreas is to balance your insulin and your glucagon. When the pancreas is called on to produce more insulin because of blood sugar elevation it will back off production of glucagon. If you don’t produce glucagon, you don’t have fat release. This is why sugar poses a major obstacle for fat release. Think of glucagon as the key to unlock the fat from your cells and into the bloodstream to be burned by your muscles.

If you are dumping a container full of sugar into your gut for two of your meals with 42 added artificial sweeteners and other misnomer ingredients instead of eating regular whole food meals, your weight loss journey will not be a successful one, nor will it be long-term.

Simple sugars, (a.k.a. donuts, cookies, cakes, Slim Fast etc.), are exactly that, they are simple sugars and thus are absorbed into the bloodstream all at once which is why you get a momentary spike in your blood sugar (aka insulin). There is no work for the digestive system to do in order to break down a simple sugar. Simple sugars signal the pancreas to produce more insulin.

Insulin helps produce energy in individuals with normal insulin regulation. When called upon it’s usually due to an elevation of blood sugar. Your blood sugar levels directly determine the amount of insulin you produce. When you experience a rush of energy from simple sugars and you have that momentary spike in your energy levels, your pancreas overreacts to this spike and sends out more insulin that is required. This is where you will receive a perceived rush of energy followed by a feeling of being tired and cranky. As you well know this sugar rush is short-term because as soon as the body works to get that blood sugar level down, you get a craving for sugar yet again in hopes of finding you more energy. This sends a message to your brain to go eat more sugar, thus when you eat sugar you crave sugar. This is a dangerous cycle that keeps you with stored fat on your body.

There are probably a million ways to lose weight. There are healthy ones; there are unhealthy ones. Slim Fast is not the best way of going about losing weight and certainly not a healthy way to go about it.

In order to lose weight, consistency and variation are the keys to results. Let’s first address consistency. When you embark upon a “diet”, it should be something that you feel you can maintain and be consistent with for a lifetime. If not, then weight re-gain becomes inevitable. From there you continue to yo-yo “diet” because you believe that you have to go back on the “diet” in order to lose the weight. You need to be consistent with a viable eating plan and vary your whole foods so your body does not become accustomed to the same foods.


Generally, the term “diet” refers to something that is done for a limited amount of time. When you approach it with that mindset instead of making lifelong habits, you have a great potential to fail. Is Slim Fast a habit you can maintain for the rest of your life? Probably not. If it will temporarily help you keep the weight off, the weight will come back. It is merely a temporary solution for as soon as you gain the weight back you will be looking for another solution to lose the weight all over again.

The best way to lose weight is to eat a lean protein, a starchy carbohydrate (brown rice, potatoes), and a fibrous carbohydrate (fruit or a vegetable) about 3 times a day and stick to the most natural, unadulterated, unprocessed foods as possible. Round out your diet with good fats such as avocados, nuts, and a supplemental fish oil, and you’re good to go.

For snacks you should plan them in between your meals and always pair a protein with a carbohydrate. By pairing a protein with a carbohydrate (starchy or fruit), you slow down the absorption of the carbohydrate into the bloodstream. The only carbohydrate you should eat alone is fibrous carbohydrates (vegetables). You should continue to eat this way until you’ve reached your weight loss goals. So, as an example, a meal plan for you might look like this:

  • Meal #1: Egg whites, oatmeal, blueberries, butter.
  • Snack #1: Greek yogurt, granola, blackberries.
  • Meal #2: Ground buffalo, flour tortilla, small salad, Greek yogurt.
  • Snack #2: Steak, brown rice, Brussels sprouts, butter with cinnamon.
  • Meal #3: Turkey breast, small salad.

As a guide, here are 3 questions I’d advise you to ask yourself BEFORE embarking upon another “diet”:

  • Is this something I can do for the rest of my life? When you go on a diet, that means you have to go off of a diet. If it does not hit you as something you can keep for a lifetime, you should probably stay away from it.
  • Does it eliminate any food groups or complete meals? Inevitably, you are not going to eat perfectly all of the time and there will be times where you will have to skip meals as there are times when things come up and you won’t be able to keep up with your regular eating schedule. The most important thing to get is that you should have a schedule to begin with and try to stay with it at least 85% of the time to maintain your weight. This way, you won’t be susceptible to every diet solution, pill, potion, book, or discovery that comes down the pike to “lose weight fast!” because you will not have any wild weight swings (yo-yoing).
  • Do you have adequate energy to fulfill your energy requirements throughout the day? This may be a sign that you are probably not eating enough throughout the day and may need to increase the size of your starchy carbohydrates by 5-10%.

I hope you accomplish your goals and please make sure you get plenty of water and rest every day too as they help the body’s systems operate optimally. Good luck!

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About Author

Velma Garnes

Velma has been an extraordinary personal trainer for 28 years and combines challenging workouts geared towards your current level of fitness with compassion, empathy, respect and humor and gets great joy out of helping her clients gain belief and trust in their own strength and abilities.


  1. Avatar

    Well that’s just wonderful. However, I don’t think there’s a whole lot of appeal to this sample menu for the rest of your life either. It’s just as unappealing and limiting as anything else. What if you don’t enjoy granola, oatmeal, yogurt or blackberries? It boils down to this: any enjoyable food eaten in quantities larger than these portions that couldn’t keep a bird alive would just make someone fat. There’s no winning. Be thin and starving and unsatisfied, or enjoy food and be overweight. Unless of course, you flood yourself with appetite suppressants, but that still won’t take away the cravings for much tastier foods. No happiness here. This sample below would not satisfy a 100 pound woman, much less an average sized grown male:

    Meal #1: Egg whites, oatmeal, blueberries, butter.
    Snack #1: Greek yogurt, granola, blackberries.
    Meal #2: Ground buffalo, flour tortilla, small salad, Greek yogurt.
    Snack #2: Steak, brown rice, Brussels sprouts, butter with cinnamon.
    Meal #3: Turkey breast, small salad.

    • shapefit

      Hi Tom – The sample menu you provided sounds delicious and very nutritious. Not sure why those clean foods would not be enough to satisfy anyone.

        • shapefit

          Hi Liz – Ground buffalo is actually available in many grocery stores across the United States. Walmart even carries different varieties. Buffalo is a great choice because it’s very lean and tastes delicious. If you don’t have access to buffalo in your area, just substitute it with lean hamburger (93/7) or a turkey burger.

  2. Avatar

    I have 2 friends that drank a shake for breakfast and sometimes for lunch as well. They started to do this with a low calorie snack here or there in between and then a smaller dinner. They didn’t exercise any more than normal. They were both around 280 pounds at 5’9″ and 5’10”. After approximately a year to 14 months they’re both down a tremendous amount of weight. They’re both under 200 pounds today. I’m not sure why you would say drinking them isn’t going to help you lose weight and keep it off but it can. It may not be the healthiest way but it works. It all depends on the person. Once they began losing weight they started to enjoy workouts a lot more. They keep the weight off by eating better nowadays and exercising regularly. But the Slim Fast drinks definitely worked for them.

    • shapefit

      Hi Zack – That’s great your friends had success with the Slim Fast drinks but they are probably a small percentage when it comes to people who have kept the weight off for the long term using mainly liquid based diets like this. If they have changed their eating habits and only supplement the shakes a few times a day then this is probably the best way to go with that program. For people who are focused on consuming the majority of their calories with liquid shakes, then it may be tough to stick with that regimen in the long run.

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