Is glucomannan for weight loss, or is it just a fad ingredient? When you’re taking your weight loss and health goals seriously, it’s good to know the facts and effects. Here, Strength Bible’s Ben Hardman looks at how glucomannan could be a great addition to your plan.
Are you wondering what the deal is with glucomannan and weight loss? Does it work? Can this type of dietary fibre really help you to lose weight?
The results from a number of human studies tell us that glucomannan can have a small yet significant impact on weight loss.
However, it’s not quite as simple as taking glucomannan and the weight drops off. The mechanisms behind exactly how glucomannan works are still up for discussion. That said, there are a few well-established theories that are backed by science.
We’ll cover these mechanisms in simple terms to give you a good understanding of glucomannan, the scenarios in which it works best, and we’ll see just how effective this supplement could be in helping you drop a few pounds in body weight.
What Is Glucomannan?
Glucomannan is a type of dietary fibre that comes from the elephant yam, or to give it its proper name, Amorphophallus konjac. This is why you may also see glucomannan marketed as ‘konjac’ or ‘konjac powder’.
Grown in the warm and wet parts of Asia, the elephant yam is a tropical-looking plant with an impressively large tuber. It’s here in the tuber and root section where glucomannan is extracted.
The konjac tuber has been used for centuries in Asian medicine as a herbal remedy and to make certain foods, including the likes of tofu and noodles.
Being a dietary fibre, glucomannan isn’t absorbed or digested by the body. In this regard, it differs from the macronutrients of carbs, proteins and fats. Instead, dietary fibre passes through our bodies relatively intact depending on whether it’s soluble or not.
Glucomannan is a water-soluble fibre. This means it forms a gel-like paste when it comes into contact with water. For this reason, it’s also used as a food thickener.
Dietary fibre could be a key ally to help people lose weight. An interesting study tracked the diets of 345 overweight or obese people who were placed on a calorie-restricted diet for 6 months.
Various factors were tracked and analysed to see how each one impacted weight loss. Against the likes of age, fat levels, changes in macronutrients and carbs, dietary fibre was the most influential factor.
With this in mind, let’s take a look at the science behind glucomannan.
The Science On Glucomannan Helping Weight Loss
There has been a fair amount of research done on glucomannan on both animals and humans. I find the science behind glucomannan’s effects on weight loss fascinating.
For this section, I’ll report back on the human-based study trials only, to make the findings as relevant as possible for you.
One of the earlier, double-blind studies on glucomannan looked at this food supplement in 20 obese subjects. Each participant took 1g of glucomannan with water an hour before each meal. They didn’t change their eating or exercise habits.
The result was a statistically significant weight loss overall.
I say statistically significant as participants lost an average of 5.5lbs over the course of eight weeks. This may not be much to write home about, but considering the participants didn’t alter their diet or exercise, it’s quite impressive.
Several other clinical studies have linked glucomannan with decreases in body weight. A number of studies on obese adults reported significant weight loss results in conjunction with glucomannan use. Interestingly, these results were seen on subjects who were on a balanced or calorie-restricted diet.
A meta-analysis of many human glucomannan studies concluded that glucomannan resulted in a statistically significant but small reduction in weight of approximately 0.79 kg (about 1%) across the board.
To provide a mini wrap-up here, it seems that glucomannan supplementation has led to significant weight loss, but significant in the scientific sense, rather than the everyday sense.
Note: As a bit of house-keeping, a statistically significant scientific result is all to do with the chances of something being a real effect as opposed to chance. Anything under a 5% probability of coming down to chance is regarded as a significant result in the eyes of scientists. I remember this threshold well from my time at university!
The results from glucomannan on weight loss are mild, but noteworthy I’d say.
How Does Glucomannan Stimulate Weight Loss?
Ok, so glucomannan can help with real-life weight loss over the short term on a fairly small scale. But how does this dietary fibre provide the help?
It’s thought that glucomannan works on a number of fronts.
It Helps You Feel Full
One of the main ways in which glucomannan aids weight loss is by promoting a feeling of fullness. It turns out that the highly viscous nature of glucomannan is the key player here.
When consumed, glucomannan absorbs water, expands and forms a gel-like substance in your stomach and gastrointestinal tract. This physical expansion of this fibre can result in the relaying of messages to tell you that you’re full up – no more food, please.
It is one of the key reasons we see it many fat burning supplements – as it helps you to keep calorie intake low.
Keeping on the physical properties, glucomannan’s viscous texture can also act to slow down the transit time of food through the small intestine and the emptying of your digestive system. In short, it slows down when you need to go to the toilet.
With food taking longer to pass through the stomach, you’re relaying messages that you don’t need any more calories.
It Dilutes The Energy Density
The likes of glucomannan and other dietary fibres have a low energy content. This is because it doesn’t get absorbed in the same way as macronutrients to provide your body with calories.
Incorporating more fibre into your diet lowers the energy-to-weight ratio of the food consumed.
Some studies suggest that people tend to eat a consistent weight of food, so adding fibre can effectively reduce the number of calories consumed for the same volume of food. In simple terms, you might end up consuming fewer calories while still feeling satisfied with the amount you have eaten.
However, going off the brain activity, it appears they’re not directly stimulated by glucomannan itself. Although it’s true that the hormone leptin will ultimately tell you when you’re feeling full.
The Benefits Beyond Weight Loss
Alongside glucomannan’s role as a weight loss aid, there are extra benefits that come with its supplementation.
- Cholesterol Management – Studies indicate that glucomannan can have a beneficial effect on cholesterol levels. In particular, glucomannan seems to reduce levels of LDL cholesterol, often referred to as ‘bad’ cholesterol. It doesn’t seem to have any significant effect on HDL cholesterol, which is ‘good’.
- Gut Health – Glucomannan’s highly fermentable nature means that it can serve as food for the good bacteria in the gut. This can potentially lead to a healthier gut microbiome, which is increasingly recognised as crucial for overall health.
- Blood Sugar Control – Glucomannan has been highlighted as a valuable addition to the diet for blood sugar control. Dietary fibres in general can slow down the digestion of food and the absorption of nutrients, which can help regulate blood sugar levels. Studies have found dietary fibres, including glucomannan, to be beneficial in patients with type 2 diabetes.
- Heart Health – In addition to helping manage cholesterol levels, reducing LDL cholesterol and its role in blood sugar control, glucomannan is likely to have benefits on heart health and reducing the risk of heart disease.
How to Use Glucomannan for Weight Loss
Glucomannan usually comes in simple-to-consume capsule and powder forms.
For weight loss, it’s recommended to take glucomannan around one hour before meals. As we’ve seen with the impacts above, glucomannan then helps to create a feeling of fullness that may reduce the consumption of further calories.
In terms of dosage, a 1g serving before meals is standard. It’s generally recommended to take 2-4g a day, which has been shown to be well-tolerated in numerous studies. It’s these levels that resulted in significant weight loss in some of the trials highlighted above.
It’s possible to take higher doses for severe cases or to help manage conditions like type 2 diabetes, but I’d recommended getting confirmation from your GP before you do this.
Who Is Glucomannan Best For?
The research indicates that glucomannan is a safe and effective supplement to use for low-level weight loss. The results aren’t extreme, but glucomannan can help you to lose weight by making you feel fuller and restricting how much you eat – essentially acting as an appetite suppressant.
The evidence from scientific studies tells us that glucomannan can be particularly beneficial for overweight and obese adults.
Although glucomannan may provide results on its own, it’s important to remember that it’s not a magic pill.
For sustainable results with weight loss, it’s best to use glucomannan alongside a diet of restricted calories, regular exercise and a healthy lifestyle. This way you’re not just getting a drop in body weight, you’re improving your overall health. This, in my view, should be the ultimate goal.