Obesity is a complex disease characterized by the accumulation of excess fat in the body that increases the risk of severe health disorders. It is caused by various factors such as an unhealthy or high-fat diet, inactivity, genetics, and stress. Obesity can be measured and classified through the body mass index (BMI). BMI is a tool that helps estimate the amount of body fat using the weight and height of an individual. The different BMI ranges that classify different weight types include;

Underweight - less than 18.5.
Healthy weight - 18.5 to 24.9.
Overweight - 25 to 29.9.
Class 1 obesity - 30 to 34.9.
Class 2 obesity - 35 to 39.9.
Class 3 obesity - more than 40.

How Does Obesity Cause Cancer?

An adult who is overweight or obese has high risk of developing cancer than healthy-weight adults. However, the correlation between obesity and cancer is not evident in children. The various mechanisms by which obesity or overweight influences cancer risk includes;

Increases oxidative stress in the body lead to chronic inflammation and affect the body’s immune response.
Produces excess sex steroid hormones such as estrogen and androgen in the body. Excess estrogen can stimulate the growth of cancer in existing breast cancer.
Obesity can stimulate production and raise the levels of insulin-growth factors. High levels of insulin-growth factors cause the development of certain cancers.

What Types of Cancers Are Linked to Being Overweight or Obese?

Being overweight or obese increases the risk of developing several cancers, including;

Colorectal cancer.
Gallbladder cancer.
Breast cancer.
Thyroid cancer.
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Prostate cancer.
Uterine cancer.
Pancreatic cancer.
Esophageal cancer.
Head and neck cancer.
Ovarian cancer.

What Is Bariatric Surgery, and How Does it Help in Weight Loss?

Bariatric surgery (also known as weight loss) refers to surgical procedures that can help people reduce weight by changing the digestive system. It is usually done in individuals when weight loss cannot be achieved by diet and exercise or in individuals who have serious health problems due to obesity or being overweight. Bariatric surgery helps in weight loss in the following ways;

It physically limits the amount of food by reducing the stomach’s storage capacity. This, in turn, limits the calorie intake.
It causes alteration in gut hormone levels which are responsible for hunger. As a result, it decreases appetite and limits food intake.
The surgery also bypasses a part of the small intestine; thus, it decreases the amount of food stored in the small intestine and limits the calorie intake.

Who Are the Ideal Candidates for Bariatric Surgery?

A person should qualify for specific criteria to have bariatric surgery. The criteria for ideal candidates for bariatric surgery include;

To be eligible for bariatric surgery, a person should be between 16 to 70 years of age.
An adult with a BMI of more than 40 or having a body weight greater than 100 pounds.
An adult with a BMI score of 35 or more with serious health problems related to obesity, such as heart disease, type 2 diabetes, hypertension, sleep apnea, and gallbladder disease.
An adult who is unable to achieve weight loss through non-surgical methods.

Bariatric surgery is contraindicated in;

Pregnant women.
Adults with an eating disorder.
Adults who have drug or alcohol addiction.
Adults who are affected by severe cardiovascular and pulmonary diseases.

What Are the Types of Bariatric Surgery?

The common types of weight loss or bariatric surgery performed are;

1. ROUX-EN-Y Gastric Bypass:

It is also known as gastric bypass surgery. It is the most commonly preferred surgical technique for weight loss in adults.

Procedure:

The ROUX-EN-Y gastric bypass surgery can be performed either laparoscopically or robotically. In this procedure, the surgeon uses laparoscopy to examine the abdominal cavity.
In ROUX-EN-Y gastric bypass surgery, a small stomach pouch of around 30 ml is created using a stapling device (a medical device used in place of sutures that helps close large wounds or incisions.)
This smaller stomach pouch limits the amount of food eaten before feeling full.
After creating the small stomach pouch, the small intestine is separated into two sections.
After separating the small intestine into two sections, the lower portion of the small intestine is attached to the newly created stomach pouch. As a result, the food directly passes into the small intestine.
Bypassing a small part of the small intestine decreases the absorption of nutrients and calories. The upper portion of the small intestine is reconnected to the lower portion, allowing the bile and pancreatic fluids to mix with the passing food digesting it completely.

The stomach pouch that is created holds less food, and due to a small portion of the small intestine getting bypassed, fewer nutrients and calories get absorbed by the body. The surgery also alters the gut hormones that lead to decreased hunger and limits the amount of food intake.

2. Sleeve Gastrectomy:

Sleeve gastrectomy is also known as laparoscopic sleeve gastrectomy or gastric

sleeve. It is a minimally invasive procedure done with the help of a laparoscope. In

sleeve gastrectomy, around 80 % part of the stomach is removed.

Procedure:

Sleeve gastrectomy is performed under general anesthesia. In sleeve gastrectomy, the surgeon cuts and removes around 80 % of the outer curved part of the stomach.
The remaining 20 % of the stomach is then stapled or sutured together, making it a banana-shaped stomach or sleeve that contains about only 25 % of the stomach’s original size. As a result, the stomach can hold only less food and limits the food intake.

Unlike gastric bypass, the stomach is removed permanently, and sleeve gastrectomy has no malabsorption.

3. Laparoscopic Adjustable Gastric Band:

The laparoscopic adjustable gastric band is a minimally invasive and completely reversible procedure performed using the laparoscope. Therefore, it is also referred to as the lap band procedure.

Procedure:

Firstly, the surgeon places a small incision near the belly button.
Through the small incision, a laparoscopic camera is inserted into the abdomen. The laparoscopic camera helps the surgeon visualize the key structures of the abdomen through the images displayed on a video monitor.
Additional incisions are made in the abdomen. Through these incisions, the surgeon inserts specialized instruments into the abdomen with the assistance of laparoscopic images displayed on the video monitor.
The surgeon inserts an inflatable gastric band on the upper portion of the abdomen to create a small pouch. The gastric band has a circular balloon filled with saline solution in it.
The band size can be readjusted, which determines the size of the stomach opening and the amount of food intake.

4. Biliopancreatic Diversion with Duodenal Switch:

It is a less commonly used weight loss procedure that entails two steps.

Procedure:

Firstly sleeve gastrectomy is done in which a major part of the stomach is removed, leaving a small banana-shaped stomach.
Secondly, a major part of the small intestine is bypassed by connecting the lower portion of the small intestine to the duodenum. This is then connected to the small tubular stomach created by sleeve gastrectomy. As a result, the food passes through the small stomach and then reaches the small intestine, which is bypassed.

What Are the Complications and Benefits of Bariatric Surgery?

The significant benefits of bariatric surgery include;

Aids in weight loss.
Helps cure obesity-related conditions like blood pressure, diabetes, obstructive sleep apnea, etc.
Improves cardiovascular health.
Relieves joint pain.
Relieves mental depression.

The common complications seen in patients after bariatric surgery include;

Abdominal pain.
Diarrhea.
Post-operative bleeding.
Dumping syndrome (a medical condition in which the food from the stomach is rapidly emptied into the small intestine).
Ascites (collection of fluid in the abdominal cavity).
Intestinal obstruction.
Minerals and nutritional deficiencies.
Limits food intake either temporarily or throughout life.

Will Weight Loss or Bariatric Surgery Help Reduce Cancer Risk?

People who undergo bariatric surgery for weight loss have a lower risk of developing cancer. It reduces the risk of obesity-associated cancers such as breast, colon, pancreatic, endometrial, and gallbladder cancer. Many studies reported that bariatric surgery reduces the risk of developing pancreatic and colon cancer by 70 % and breast cancer by 85 %. Besides reducing cancer risk, it also reduces the rates of cancer-related deaths.

Conclusion:

Bariatric surgery can reduce cancer risk in patients who are obese or overweight. Besides lowering cancer risk, it also helps relieve various obesity-related conditions like diabetes, hypertension, cardiovascular diseases, etc. However, although it has numerous benefits, it also leads to severe complications in individuals.