Important Points:
- Obesity
- Malnourished
- Nutrient intake
- Vitamin deficiency
- Starvation
Malnutrition is Both Obesity and Starvation
Yes, you can be obese and malnourished at the same time. Malnutrition means poor nutrition in either direction: too few nutrients, or more calories than you need. A diet of pizza, fries, pasta and cakes gives plenty of calories but few vitamins and minerals.
We usually link the word malnutrition with the tragically thin people in TV news reports of third world famines. In fact, it’s a shockingly common problem all over the world. Not at starvation level, but millions of patients aren’t getting enough calories, protein, vitamins, and minerals.
Doctors say we lean more and more on fast food, and binge-drinking rates keep rising. Because of that, many people lack the vitamins and minerals they need for health. In the most extreme cases, the result is pot-bellies, wasted limbs and emaciated (very thin) bodies. These are all conditions more often associated with famine victims in the developing world. Malnutrition can be fatal. In milder forms, it can cause a host of symptoms that affect everyday life, from hair loss and muscle wasting to food cravings and lethargy (low energy). It is possible to be obese and still be malnourished.
1. What is Malnutrition?
Malnutrition is a serious condition. It happens when a person’s diet doesn’t have the right amount of nutrients. Malnutrition means “poor nutrition” and can refer to:
- undernutrition – when you don’t get enough nutrients
- overnutrition – when you get more nutrients than you need
2. Who is Affected by Malnutrition?
Malnutrition is a common health problem. An estimated 3 million people in the UK are malnourished at any time, and many more are at risk. Around one in three people admitted to hospital or care homes in the UK are found to be malnourished or at risk of it.
Malnutrition is caused by a poor diet or by a problem absorbing nutrients from food. That can come from reduced mobility, a long-term health condition, or a low income.
3. What are the Signs of Malnutrition?
The most common symptom of undernutrition is weight loss you did not plan (losing 5-10% or more of your body weight over three to six months). Other signs include weak muscles, fatigue, low mood, and more illnesses or infections.
The main sign of overnutrition is being overweight or obese. But people with undernutrition can also be overweight if they eat a diet high in energy (calories) but low in other nutrients.
4. Why are so many obese people undernourished?
The number of people who are malnourished despite being obese is shocking, a leading weight loss surgeon said today. A recent study showed that despite high levels of obesity in the U.S., many people are undernourished.
A diet of pizza, fries, chips, pasta, rice, cookies, cakes leaves many people eating a lot of calories but few nutrients. So says Dr. Sally Norton, an NHS consultant who specializes in weight loss and upper gastrointestinal surgery.
Drug companies push sales of expensive drugs that treat the symptoms of the disease but not the cause. The multi-million-dollar drug industry encourages doctors to use expensive drugs, not healthier food. It wants them to treat type 2 diabetes, high cholesterol, heart disease and other conditions tied to poor nutrition that way.
Hippocrates, the father of medicine, was so right when he said, over 2,000 years ago: ‘let food be thy medicine’. And yet, jump to the 21st century. A recent study shows that many Americans, despite their access to plenty of food, are undernourished.
5. Can obese people really be malnourished?
Picture a malnourished hospital patient…..
The person you’re picturing probably doesn’t weigh 300 pounds, does she? Yet obese patients can develop malnutrition before or during a hospital stay. They have worse outcomes because of it.
In fact, a recent study found that malnutrition cancels out the “obesity paradox,” the idea that, among the critically ill, heavier patients do better than normal- or underweight patients. Researchers looked specifically at malnourished obese patients. They had a higher risk of death than well-nourished patients of similar body mass index. The results were published in the January issue of Critical Care Medicine.
Yet experts say hospital clinicians often miss these patients’ nutritional deficiencies. “We as physicians don’t necessarily have a great handle on who is malnourished,” said Kenneth B. Christopher, MD, co-author of the study. “You can always tell if someone’s profoundly malnourished, because they start appearing to be cachectic, but it’s less severe degrees of malnutrition that are actually harder to see.”
Judging by looks is one problem. A number of other factors can also make it hard to diagnose or prevent malnutrition in obese hospital patients. These include gaps in history taking, limits of lab testing, and challenges in getting nutrition to patients. Experts say hospitalists can help close these gaps. They can do this if they raise their own level of suspicion and work with the health care team to focus on patients’ nutritional status.
Malnutrition can be fatal. In milder forms, it can cause a host of symptoms that affect everyday life. How many nutrients do you get in cookies, pieces of cake, chips, fries, pizza, white rice, pasta and bread? Not a whole lot. Foods like these are harmful, refined grains most of all, so cut them out. Get your nutrients from real, fresh, whole foods instead.
6. How is malnutrition diagnosed in someone with obesity?
Accurate screening for malnutrition starts with knowing you can’t see it with your eyes or even a scale. “Nutritional status is not body mass index,” summed up Dr. Christopher, a nephrologist (kidney doctor) and critical care specialist at Brigham and Women’s Hospital in Boston. For one thing, extra weight may not be body fat.
Obesity could also hide recent weight loss, an important marker of malnutrition. “Somebody could be obese but have a gastrointestinal problem and have been losing weight. Even though they’ve lost a considerable amount of weight, they started off so obese that they’re still technically obese,” said Dr. Mechanick.
“Because our society has so much stigma around overweight and obesity, when many obese people lose weight, however they lose it, they get more positive feedback,” said Charlene W. Compher, PhD, a professor of nutrition science at the University of Pennsylvania in Philadelphia. If a patient lost weight from bariatric surgery, he is at special risk for malnutrition. “The odds of having vitamin deficiencies are very high with patients with gastric bypass, especially if they do not take all of the vitamin and mineral supplements that they are instructed to,” said Dr. Compher. An obese person could be getting enough calories but not enough protein or other nutrients, because of an unhealthy diet.
7. How Can You Tell if You’re Malnourished?
“There’s no lab test for malnutrition,” said Dr. Kirkland. “People rely on albumin. It’s not helpful for malnutrition. Albumin just reflects the acuity of illness or the duration of malnutrition, but not the severity of it or the presence of it.”
Whatever your weight, always eat well balanced, healthy meals, with regular supplements where needed. That matters because malnutrition could potentially lead to other chronic illnesses such as type 2 diabetes, heart issues and others.
Frequently asked questions
What does severe malnourishment look like?
In its most extreme form, malnutrition shows up as pot-bellies, wasted limbs and emaciated bodies, the look most people link with famine. Doctors call a profoundly malnourished person cachectic (wasted). Milder malnutrition is much harder to see. In a person with obesity, it can hide completely behind their weight.
What problems can malnutrition cause?
Mild malnutrition causes everyday symptoms such as hair loss, muscle wasting, food cravings and lethargy. Undernutrition also brings weak muscles, fatigue, low mood and more illnesses and infections. Over time, poor nutrition can lead to chronic illness, including type 2 diabetes and heart problems. And malnutrition can be fatal.
Can you be malnourished and not know it?
Yes. You cannot see malnutrition with your eyes or a scale, and there is no single lab test for it. Albumin, the blood test many people rely on, does not show whether malnutrition is present. Someone who is still obese after losing a lot of weight, or who has had gastric bypass, can be malnourished without anyone noticing.
Related reading
- Food Addiction and Hyperpalatable Food: How It Works
- The Secret to a Healthy Weight: Insulin, Not Calories
References:
- International Journal of Obesity (2019): Overfed but undernourished: recognizing nutritional inadequacies/deficiencies in patients with overweight or obesity. Retrieved from
https://www.nature.com/articles/s41366-018-0143-9
- NCBI (2012): The Malnutrition of Obesity: Micronutrient Deficiencies That Promote Diabetes. Retrieved from
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3313629/
- ACP Hospitalist (2015): Obesity and malnutrition are not mutually exclusive. Retrieved from
https://acphospitalist.org/archives/2015/02/nutrition.htm
- Critical Care Medicine (2015): The True Obesity Paradox
Obese and Malnourished? Retrieved from
- NHS Inform (2019): Malnutrition. Retrieved from
https://www.nhsinform.scot/illnesses-and-conditions/nutritional/malnutrition
Medically reviewed by Dr. Gurpreet Singh Padda, MD, MBA, MHP
Interventional pain physician, addiction medicine specialist and obesity medicine diplomate.
Licensed in Missouri and Illinois.
Last reviewed June 18, 2026
