Usually weight loss occurs when your body is not getting as much calories as it is utilizing. This kind of weight loss takes some time and is not a cause for concern. However, when the weight loss is rapid and unintentional then it can be a cause for concern. Some of the common causes of sudden weight loss in men include crash diets, Bulimia and bariatric surgery.

Crash Diets

A crash diet is an intense diet plan that strictly limits a person’s calorie intake. By consuming calories less than the body’s requirement, a person forces the body to utilize calories stored in the body, leading to weight loss. Besides burning the fat fast, it also causes a decrease in muscle mass and the person starts feeling weak and fatigued due to malnutrition.


Bulimia is an eating disorder where a person forcefully vomits after consuming food to reduce the amount of calories he/she has just taken in. The effect of bulimia is similar to crash diet – limiting the calorie intake and causing rapid weight loss. Another dangerous aspect of this eating disorder is that the person becomes obsessed to vomiting and cannot stop even after reaching a healthy weight, and becomes severely underweight.

Bariatric Surgery

Bariatric surgery is a surgical procedure carried out to induce weight loss in a person. It includes stomach stapling, lap band surgery and gastric bypass. These type of surgeries limit the amount of food you can consume before feeling full, thus reducing your daily calorie intake. After undergoing a bariatric surgery, weight loss of a couple of pounds every week is normal, but if you are losing weight rapidly then it may be a cause for concern, you must see your doctor at the earliest.

Disease and illness

If none of the above mentioned situations suits you, then you must undergo a thorough clinical examination, it may be a symptom of some serious illness. If you have recently experienced sudden weight loss then take it serious and consult your physician at the earliest. A detailed health history is the first step in finding out the causes of rapid unintentional weight loss. Your doctor may ask you questions like, when did the weight loss begin, how much weight have you lost over the last four weeks, has your appetite or activity level changed, or have there been any changes in bladder or bowel routines. To determine the causes of unintentional, sudden weight loss accurately, you may also be recommended blood and urine tests, ultrasounds, X-rays or any other physical exam.