Achieve Natural Weight Loss with Chitosan

    Chitosan is known for its notable ability to inhibit fat digestion. Structurally, chitosan is a linear polysaccharide obtained from chitin through a process called deacetylation. Chitin itself is the second most abundant natural polysaccharide after cellulose. Chemically, chitosan consists of randomly arranged β-(1–4)-linked units of D-glucosamine (deacetylated) and N-acetyl-D-glucosamine (acetylated).

    The anti-obesity effects of chitosan primarily result from its strong inhibition of fat digestion. When consumed, gastric acid in the stomach dissolves chitosan, allowing it to bind with dietary fats and form a chitosan-fat complex. This complex subsequently solidifies into a gel-like substance in the small intestine. As a result, the fats entrapped within this gel cannot be absorbed and are instead excreted in the feces. Several human studies have reported the weight-loss benefits of chitosan.

    In a study conducted in New Zealand, researchers investigated chitosan's effectiveness for weight loss among overweight and obese adults. This was a 24-week randomized, double-blind, placebo-controlled trial at the University of Auckland from November 2001 to December 2002, involving 250 participants, 82% of whom were women. Participants had an average age of 48 years (±12) and an average body mass index (BMI) of 35.5 kg/m² (±5.1) (1).

    Participants were randomly divided into two groups, with 125 individuals receiving 3 grams of chitosan daily and the other 125 receiving a placebo. Both groups received the same standardized advice on diet and lifestyle for weight loss, and capsule counts were used to monitor adherence to the treatment (1).

    The primary measure was the change in body weight, with other health markers including BMI, waist circumference, body fat percentage, blood pressure, cholesterol levels, blood sugar, fat-soluble vitamin levels, fat in stool, and quality of life also being monitored (1).

    By the end of the trial, participants taking chitosan lost slightly more weight than those taking the placebo. The chitosan group experienced an average loss of 0.4 kg (±0.2), representing about a 0.4% decrease in body weight, while the placebo group gained 0.2 kg (±0.2), a 0.2% increase. This difference was statistically significant (p=0.03), although the weight loss itself was modest (1).

    The chitosan group also showed small improvements in total cholesterol, LDL (bad) cholesterol, and blood glucose levels (p<0.01), though these improvements were minimal. There were no significant differences between groups for the other measured health markers. This study concluded that over the 24 weeks, chitosan led to only a minor weight loss compared to the placebo. Although statistically significant, the difference was not large enough to be clinically meaningful (1).

    In another clinical study conducted in India, 96 overweight and obese adults were randomly divided into two groups: 64 participants took five chitosan capsules daily (each capsule contained 500 mg, totaling 2.5 g/day), and 32 participants took placebo capsules without active ingredients. Participants took one capsule in the morning, two capsules 15 minutes before lunch, and two capsules 15 minutes before dinner with a glass of water. This 90-day study did not require dietary restrictions (2).

    Researchers measured body weight, body composition (fat and muscle), anthropometric parameters, HbA1C levels (blood sugar control indicator), and lipid profiles at 45 and 90 days. Participants also completed a Quality of Life (QoL) questionnaire (Short Form-36), and their calorie intake was recorded. Safety was evaluated by monitoring adverse events (2).

    Participants taking chitosan lost an average of 1.78 ± 1.37 kg after 45 days, and by day 90, the average weight loss increased to 3.10 ± 1.95 kg, significantly greater than the placebo group (p < 0.0001). Specifically, the chitosan group's weight decreased from 80.13 ± 11.47 kg at baseline to 77.75 ± 11.56 kg at 45 days and further to 76.89 ± 11.88 kg by day 90, a statistically significant reduction (p <0.0001) compared to baseline. In contrast, the placebo group's body weight minimally changed from 80.54 ± 12.68 kg at baseline to 80.89 ± 12.15 kg at day 45 and 80.76 ± 12.31 kg by day 90, changes that were not statistically significant (2).

    Additionally, the chitosan group experienced improvements in body composition, body fat, waist measurements, and QoL scores. Chitosan also lowered HbA1C levels below 6% for participants who started with higher levels. Participants' calorie intake remained consistent throughout, indicating dietary habits did not significantly change. Lipid levels did not significantly differ. Side effects were mild and not related to chitosan use (2).

    In conclusion, fungal-derived chitosan facilitated a weight loss of about 3 kg over 90 days without diet modifications. It also improved body composition, body measurements, blood sugar control, and quality of life, and was found to be safe and well-tolerated (2).

    A randomized, placebo-controlled, double-blind study in South Korea involved 80 healthy college women (aged 20–30) for 8 weeks. Subjects were randomly divided into three groups: Control (placebo, n=26), Chito (3 g/day chitosan, n=27), and Chito-vita (3 g/day chitosan plus 2 g/day L-ascorbic acid, n=27) (3).

    Body weight and BMI significantly decreased in the Chito and Chito-vita groups (p<0.05) compared to the Control group. Additionally, the Chito-vita group had a significantly greater BMI reduction compared to the Chito group (Chito: -1.0 kg/m² vs. Chito-vita: -1.6 kg/m², p<0.05). Weight reductions were approximately 4 kg in the Chito-vita group and around 2.5 kg in the Chito group, versus less than 1 kg in the Control group. Fat mass, body fat percentage, circumference measurements, and skinfold thickness decreased more in chitosan groups but were not statistically significantly different among the groups. The combination of chitosan with L-ascorbic acid may aid body weight control (3).

    In a U.S. study, researchers evaluated whether a chitosan supplement was effective for improving body composition under everyday conditions. This randomized, double-blind, placebo-controlled trial initially enrolled 150 overweight adults, with 134 completing the 60-day study (89.3%), of whom 111 (82.8%) were women distributed evenly across three groups (4).

    Participants taking chitosan (3 g/day, in six capsules of 500 mg each) lost significantly more weight (-2.8 lbs vs. +0.8 lbs, p<0.001) and fat mass (-2.6 lbs vs. +0.1 lbs, p=0.006) compared to controls. When compared to placebo, the treatment group also showed greater improvements in weight (-2.8 lbs vs. -0.6 lbs, p=0.03), body fat percentage (-0.8% vs. +0.4%, p=0.003), and fat mass (-2.6 lbs vs. +0.6 lbs, p=0.001). They also had better scores on the Body Composition Improvement index (BCI) (+2.4 lbs vs. -1.9 lbs, p=0.002). This suggests chitosan effectively reduces body fat while preserving muscle mass in typical daily conditions (4).

    Chitosan, as a soluble fiber, can lower the glycemic index of food, thereby slowing calorie absorption and reducing immediate insulin demand, which favors calorie utilization rather than storage as fat. Its fat-binding ability, gel formation in the digestive tract, and positive charge help capture and excrete dietary fats and bile acids, further reducing fat absorption.

    Overall, chitosan supplements have shown consistent, though generally modest, weight loss effects in human trials. Additionally, chitosan can help improve other health markers, such as cholesterol and glucose levels, and is considered safe and well-tolerated.

References:

1.     Mhurchu CN, Poppitt SD, McGill AT, Leahy FE, Bennett DA, Lin RB, Ormrod D, Ward L, Strik C, Rodgers A. The effect of the dietary supplement, Chitosan, on body weight: a randomised controlled trial in 250 overweight and obese adults. Int J Obes Relat Metab Disord. 2004 Sep;28(9):1149-56. doi: 10.1038/sj.ijo.0802693. PMID: 15311218.

2.     Trivedi VR, Satia MC, Deschamps A, Maquet V, Shah RB, Zinzuwadia PH, Trivedi JV. Single-blind, placebo controlled randomised clinical study of chitosan for body weight reduction. Nutr J. 2016 Jan 8;15:3. doi: 10.1186/s12937-016-0122-8. PMID: 26747458; PMCID: PMC4706713.

3.     Jung EY, Jun SC, Chang UJ, Suh HJ. L-ascorbic acid addition to chitosan reduces body weight in overweight women. Int J Vitam Nutr Res. 2014;84(1-2):5-11. doi: 10.1024/0300-9831/a000187. PMID: 25835230.

4.     Kaats GR, Michalek JE, Preuss HG. Evaluating efficacy of a chitosan product using a double-blinded, placebo-controlled protocol. J Am Coll Nutr. 2006 Oct;25(5):389-94. doi: 10.1080/07315724.2006.10719550. PMID: 17031007.

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