What Effects Does Lactose Have on the Human Body?

Office workers with milk and cookies, smiling, side view
Two people have glasses of milk and cookies. (Image: Noel Hendrickson/Photodisc/Getty Images)

A type of carbohydrate, you'll find lactose in milk and milk products. It is a disaccharide, or a sugar molecule, consisting of two sugars – glucose and galactose. In addition to dairy, lactose might also be in processed foods, because manufacturers add milk derivatives to products such as baked goods, pancake mix, processed meats and coffee creamers. Lactose can have both positive and negative effects on your body.

Energy

Carbohydrates are the macronutrients your body prefers as its primary energy source. Therefore, lactose can serve as fuel to power your activities. Once your body digests lactose, the sugars enter your cells, where they are metabolized for energy. Your body uses the energy to fuel your physical exercise and to maintain your basal metabolism. In addition, consuming lactose spares your dietary protein from serving as an energy source, allowing it, instead, to build muscle and perform its other maintenance functions.

Weight Gain

If the calories you take in outnumber the calories you burn, the excess stores as fat. For example, if you consume more lactose than you need, your body will convert the sugars it doesn’t burn to fatty acids. These fatty acids accumulate in your adipose tissue as an energy reserve. Therefore, a high lactose intake can result in weight gain, depending on your overall calorie expenditure. Excessive weight gain can lead to obesity, a condition of extreme overweight that increases your risk for cancer, cardiovascular disorders and type 2 diabetes.

Digestive Problems

Before your body can benefit from the energy contained in lactose, you must digest it to its constituent monosaccharides through the action of the digestive enzyme lactase. However, your intestinal cells may not make any, or enough, lactase to accomplish digestion. In this condition, called lactose intolerance, the undigested lactose traveling through your gastrointestinal tract can cause digestive upset. Common symptoms of lactose intolerance include abdominal pain, bloating, nausea, gas and loose stools.

Considerations

To mitigate the negative effects of lactose on your body, you can adjust your diet depending on the problem this sugar causes. If the lactose you consume from milk products leads to excessive calorie consumption, you might need to reduce your intake or increase your physical activity level. If lactose causes digestive distress, you can either avoid high-lactose food products or take commercially available lactase supplements when consuming lactose-rich foods.

REFERENCES & RESOURCES
Load comments
PARTNER & LICENSEE OF THE LIVESTRONG FOUNDATION

Copyright © 2019 Leaf Group Ltd. Use of this web site constitutes acceptance of the LIVESTRONG.COM Terms of Use, Privacy Policy and Copyright Policy. The material appearing on LIVESTRONG.COM is for educational use only. It should not be used as a substitute for professional medical advice, diagnosis or treatment. LIVESTRONG is a registered trademark of the LIVESTRONG Foundation. The LIVESTRONG Foundation and LIVESTRONG.COM do not endorse any of the products or services that are advertised on the web site. Moreover, we do not select every advertiser or advertisement that appears on the web site-many of the advertisements are served by third party advertising companies.