Can Insulin Cause Weight Gain?

insulin and weight gain

Most people know that insulin has something to do with diabetes and blood glucose, but there is much more to insulin. Before we learn more about the insulin and its effect on the weight of the person, let us first understand some basics.

What does insulin do?

Insulin affects the carbohydrate, lipids (fats) and protein metabolism. Our body cells need glucose to fulfill their energy needs, which is provided by carbohydrates. Insulin is required for glucose to enter into the various cells, especially muscular cells. Insulin also makes sure that the excess of glucose is either converted to glycogen and stored in the liver or changed to fat and stored in adipose tissues (kind of fat storage tissues). Thus insulin helps to control the level of glucose in blood and play a vital role in its utilization by various body tissues(“Physiologic Effects of Insulin,” n.d.).

Insulin inhibits fat breakdown from the adipose tissues, helps to store excess of energy in the form of fats. It is also needed to transport amino acids (building blocks of the body, derived from proteins) to various body cell, thus having an anabolic effect. Insulin is also needed for proper usage of the different electrolytes, especially potassium (“Physiologic Effects of Insulin,” n.d.).

Diabetes and relation to insulin

Diabetes is caused due to either deficit of insulin or inability of our body to use the insulin (called insulin resistance). Mostly, both these factors play the role(Ferrannini, 1998), resulting in increased blood glucose levels. The level of blood glucose above normal is highly damaging to various body tissues, in particular for blood vessels and nerve tissues. Thus high blood glucose increases the risk of heart diseases, weakens our eye-sight, damages the kidney and decreases the sensory abilities, making us prone to various problems like foot ulcers(Ackermann & Hart, 2013).

In most of the people, the doctor would start treatment with some oral tablets (except in type 1 diabetes, which affects less than 10% of diabetics). But earlier or later tablets stop helping and insulin is needed to treat diabetes. Insulin is one of the most efficient and safe ways to treat diabetes, quite often doctor may give insulin in combination with oral drugs(Scheen, Castillo, & Lefèbvre, 1993).

Treatment of diabetes and weight of a person

All the medicines used in diabetes are either weight neutral or increase the body weight or decrease the body weight(Hermansen & Mortensen, 2007). Insulin is among those that increases the body-weight. The increase in weight is harmful to people with diabetes. Moreover, many of people who have diabetes are already overweight. This increase in body weight decreases the effectiveness of therapy and increases the risks of complications from diabetes(Dailey, Admane, Mercier, & Owens, 2010; Khan, 2004).
Thus the diabetes specialist has to choose the drugs or insulin therapy by keeping in mind the effect on body-weight of any such treatment. Usually, this weight gain can be countered with a proper combination of drugs and non-pharmacological measures. Moreover, new drugs are emerging, which are either weight neutral or help to lose weight(Seshadri & Kirubha, 2009).

How does insulin cause weight gain?

A large number of people with diabetes are already overweight; these are the people with positive energy balance (more calorie intake as compared to spent), lower basal metabolic rate (body spends less energy while at rest)(Al-Goblan, Al-Alfi, & Khan, 2014). People with uncontrolled diabetes lose lots of glucose through the urine (called glycosuria by doctors). Individuals with high blood-glucose levels are also dehydrated as their body try to get rid of excess glucose through increased urine output. Similarly, they feel more hunger as body fails to use the glucose properly(“The Big Three Diabetes Signs,” n.d.).

But once the person starts taking insulin, all these processes are stopped, in the initial phase, many may see a quick gain in weight. It is because the body becomes hydrated again, it stops losing glucose through urine, body’s ability to store glucose and fats improve, in fact, there is an improvement in all anabolic processes(“Insulin Weight Gain | Joslin Diabetes Center,” n.d.).

Thus to some extent, this initial weight gain is just an indicator of the effectiveness of insulin therapy and normalization of various anabolic processes in the body. Another reason for continued weight gain is that after the insulin there is need to decrease the food intake which many does not do. People with uncontrolled diabetes have more appetite to compensate the glucose hunger of cells (in uncontrolled diabetes glucose is more in blood, but not in cells)(Bode, 2006).

How can we prevent the weight gain from insulin?

Some people make the mistake of discontinuing the insulin to lose weight, on resuming the insulin therapy they may gain even more weight. Discontinuation of insulin would be more harmful to health than weight gain. One need to clearly understand that controlling the blood sugar is the primary target of diabetes treatment, avoiding the weight gain due to therapy is only secondary to it.

Thus what we must understand that once started, insulin therapy should never be discontinued. But your doctor can make certain adjustments to optimize it. Further, your doctor can add certain drugs to counter the weight gain, and decrease the need for insulin (Carver, 2006).

Most important to understand is that weather to prevent diabetes or to control it, lifestyle changes remain critical, after all, diabetes is a disease caused by the wrong way of life.
Therefore, to control weight during the therapy with insulin in diabetes one can take the following measures(“Insulin and weight gain,” n.d.):

  • Dietary measures: cut down your calories, eat food in small portions, be heavy on fruits and vegetables. Food rich in dietary fiber also helps to improve intestinal motility and reduce weight. Keep yourself well hydrated by drinking lots of water, but avoid sugary drinks and packed juices(“What is a healthy, balanced diet for diabetes? – Diabetes UK,” n.d.).
  • Physical activity: increase physical activity. Latest research shows that 150 minutes a week of exercise like brisk walking, cycling, gardening or doing some sports give best results(Colberg et al., 2010). Exercising too much may also fail to decrease weight due to increase in appetite. Further resistance training (training with weights) twice a week can help a lot. Latest research shows that sedentary lifestyle (lack of exercise) is becoming the most important disease causing reason(Choices, 2017).
  • Consult your doctor about medications: some anti-diabetic drugs can be helpful in losing weight or countering the weight gain due to insulin therapy. One such drug which helps to increase the effectiveness of insulin and decrease weight is metformin (insulin sensitizer)(Mäkimattila, Nikkilä, & Yki-Järvinen, 1999), other options could be drugs like voglibose or orlistat (these drugs help by decreasing the absorption of carbohydrates or fats)(Heller, 2004).
  • Keep taking insulin regularly: yes, never discontinue it due to weight gain, as discontinuation is much worse for your health than some weight gain. Also, remember if you gain weight on starting insulin, it does not mean that you will keep on putting the weight. Some types of insulins cause less weight gain as compared to others, ask your doctor about it if you are overweight or gaining too much weight(Haak, Tiengo, Draeger, Suntum, & Waldhäusl, 2005).


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