Chronic Fatigue Syndrome (CFS), also known as myalgic encephalomyelitis (ME/CFS), is a complex, debilitating medical condition affecting multiple systems within the body. Characterized primarily by persistent, unexplained fatigue, CFS can significantly impair a person's ability to function in daily life. While fatigue is the hallmark symptom, many other symptoms can manifest, including gastrointestinal issues, cognitive difficulties, and musculoskeletal pain. The impact of symptoms on everyday functioning varies widely in severity. People with mild ME/CFS may be able to do some light domestic tasks such as cooking (sometimes needing support), whereas people with moderate or severe ME/CFS may be more restricted in their activities. This article explores the intricate relationship between chronic fatigue syndrome and weight loss, addressing potential causes, management strategies, and dietary considerations.
Understanding Chronic Fatigue Syndrome
As the name suggests, fatigue is the hallmark sign of chronic fatigue syndrome (CFS). It usually occurs suddenly, although some people develop it gradually, and lasts for 6 months or more. It often follows what appears to be a cold or flu-like condition. The fatigue is so severe that it can impair your ability to work. Resting often does not help alleviate the symptoms. The fatigue will develop after even mild physical exertion or after partaking in an activity that requires mental acuity, such as working on a computer. Other symptoms observed are waking up unrefreshed, memory or concentration problems, worsening symptoms when standing up, aching joints and muscles, nausea, a sore throat, and headaches.
The exact cause of CFS is unknown. It may be associated with specific types of infections such as Epstein-Barr or Lyme disease. It may also be an autoimmune disease, causing the immune system that usually protects the body to instead attack its cells. There is no cure for chronic fatigue syndrome, but treatment is individualized and usually targets specific symptoms.
Weight Changes and Chronic Fatigue Syndrome
The relationship between CFS and weight is complex and can manifest differently in individuals. While some individuals with CFS may experience weight gain, others might struggle with weight loss.
Weight Gain in CFS
Weight gain is something that my clients frequently ask me about as they address Chronic Fatigue and other Chronic Illnesses. Weight gain can be a difficult and challenging consequence of being unwell for various reasons. As the saying goes; with knowledge comes power, or in this case, empowerment. People experience weight gain as a consequence of chronic illness for a variety of reasons. An overly simplistic way of viewing weight maintenance is to burn calories in alignment with what you consume. When someone becomes chronically ill, especially when the illness has a fatigue component, they will naturally move less and expend less energy. When chronically unwell, we can only move as much as the body will allow. Pushing yourself to exercise above your tolerance to avoid weight gain will likely sabotage your recovery efforts and delay weight loss longer term. What we don’t use, we lose. Therefore, a sedentary lifestyle and lack of stimulus to muscle tissue can lead to loss of muscle mass. Muscle is metabolically active tissue which means that the more muscle mass someone has, the more energy they will burn on a daily basis. Loss of muscle mass can result in a further slowing of your metabolic rate. Metabolic dysfunction means that there is suboptimal functioning of the metabolism. The consequence is poor use and metabolism of fuels and an increase in fuel storage.
Read also: Nutrition and stage 2 CKD
Some medications cause weight gain, water retention or increased appetite and cravings which make it easier to gain weight. Being chronically unwell is hard. There are better days, maybe even some good days and then there are the hard days. Some people, depending on their nervous system, may seek comfort in food. The current study investigated weight trends over time in a community-based sample of individuals with CFS and healthy controls. It further investigated the impact of co-morbid weight issues on a number of health and disability outcomes with a subset of overweight individuals. Overweight and obese individuals with CFS demonstrated poorer functioning than controls that were similarly weighted. One participant was excluded because she had gained weight at follow up and her BMI was > 40 kg/m2. Due to the debilitating nature of CFS, patients have been known to substantially reduce their occupational, social, educational, and personal activities, which over time may result in the type of weight gain that can become an exclusionary factor of CFS. Furthermore, there is growing evidence that people with CFS may have aerobic metabolic dysfunction causing pathological fatigue and post-exertional malaise. Both fatigue and post-exertional malaise can lead to weight gain, as patients who are severly fatigued may not have the energy required to exercise.
Weight Loss in CFS
Weight loss is not a symptom of ME/CFS and does not form part of the underlying disease process in ME/CFS. In fact, many people with ME/CFS report thattheir weight has increased due to the restrictions on activity and exercise that this illness imposes. However, people with ME/CFS who have no other medical problems do sometimes lose weight. In this case there is normally a fairly obvious explanation such as poor nutrition, being on a restrictive diet, or loss of appetite. When weight loss is significant - as you describe this indicates that other explanations must be considered and, where appropriate, investigated.
There is a long list of conditions that can cause weight loss. Important ones that have symptoms which overlap with ME/CFS and should always be considered include: Inflammatory bowel disease - ulcerative colitis or Crohn’s disease - where there are bowel symptoms as well Thyrotoxicosis - having over active thyroid gland - which can also cause palpitations and excessive sweating Anxiety or depression Prescription drugs can sometimes cause weight loss as a side-effect. Examples include SSRI antidepressants, anticonvulsants and antidiabetic drugs. So this is a symptom that you must go and see your doctor about as soon as possible. Your doctor should take a full history, carry out a physical examination, and arrange some blood and urine tests. You could be referred to hospital if it is felt that another opinion or further investigation is required. If no explanation is found, and you need to gain some weight, information and guidance from a dietitian can be helpful.
Dietary Considerations for Managing Weight and CFS Symptoms
Along with the above-mentioned symptoms of chronic fatigue syndrome, many people suffer from problems with their gastrointestinal system. Heartburn, gas, nausea, diarrhea, constipation, and cramps are all problems that may be experienced with CFS. In addition, many people with CFS have other health conditions, complicating what foods can be tolerated. It is important for you to pay attention to your body and figure out what is right for you. People who have chronic fatigue syndrome often have problems with cell metabolism, malabsorption, food sensitivities, bladder sensitivities, and blood sugar regulation problems. CFS may hamper your ability to eat or digest large meals, so small and frequent meals may work better. Some people with CFS can only tolerate a vegan diet, while others may need meat with every meal. It is important for you to listen to your body. Pay attention to how your body reacts to different foods-even keep a food diary. If you experience nausea, insomnia, headaches, anxiety, gas, diarrhea, or constipation after eating certain foods, avoid them in the future.
Foods to Limit or Avoid
Stimulants like those found in tea, coffee, chocolate, and some supplements should be avoided. Alcohol is particularly discouraged for people with CFS. Alcohol depresses the central nervous system, is toxic to the liver, interferes with metabolism, and causes your arteries and veins to dilate. Sweeteners are also something to be avoided. This includes sugar, corn syrup, sucrose, sucralose, and other artificial sweeteners. People with CFS often have problems with low blood sugar. These substances can cause a rapid increase in blood sugar, followed by a quick decline. Animal Fats are another food source that can worsen CFS. If you have chronic fatigue syndrome, you may already have an impaired liver and gallbladder, which are necessary for the metabolism of fats. Food Additives may make your food more appetizing, but they add no nutritional value and will do you more harm than good. Many additives contain petrochemicals, which often cause sensitivity reactions. If you have a sensitivity to any additives, you may experience inflammation, itching, pain, insomnia, depression, hyperactivity, and headaches.
Read also: Diet's Impact on Chronic Pain
General Dietary Recommendations
If you suspect or have a diagnosis of ME/CFS, it is important to maintain a healthy, balanced diet with adequate fluid intake. This will aid energy management and help manage your symptoms. The NHS Eatwell Guide shows how much of what we eat overall should come from each food group to achieve this. Base your meals on potatoes, bread, rice, pasta or other starchy carbohydrates, as they are a good source of energy. Aim to choose ‘lower GI’ carbohydrates that release energy more slowly (e.g. Beans, pulses, fish, eggs and meat are a good source of protein, vitamins and minerals. Milk, cheese and yoghurt are a source of protein and some vitamins. They’re also an important source of calcium, which helps keep bones healthy. Drink plenty of fluids - water, milk and sugar-free drinks all count. Fruit juice and smoothies also count, but limit these to 150ml per day. Some people with ME/CFS find that they are more sensitive to caffeine, so you may find it helpful to reduce tea and coffee, or switch to decaffeinated. There is a lot of conflicting information about ME/CFS and diet online. There is no scientific evidence to support the use of restrictive diets in ME/CFS, which can use up time, energy and money, as well as leaving you vulnerable to nutritional deficiencies. This can occur if you are restricting your diet, have a reduced appetite (for example due to taste changes or nausea), or are having difficulty swallowing and chewing. If you become malnourished, this could make you more vulnerable to illness. It may help to eat little and often, choose softer foods that are easier to eat, and have nourishing snacks and drinks between meals. On the other hand, you may find that you gain weight because you are less physically active, or have an increased appetite. If this is the case, try to reduce sweet or fatty snacks and drinks and consider your portion sizes. Many people with ME/CFS report IBS-like symptoms, including constipation, diarrhoea and/or bloating. If your IBS symptoms persist after following the advice in the leaflet, talk to your GP. You may benefit from referral to a dietitian, who can assess your suitability for the low FODMAP diet. This is a short-term, three stage food elimination and reintroduction process. If you are experiencing nausea, make sure you keep up adequate fluid intake and eat regularly, having small amounts often.
The Role of Calorie Restriction
The main use of calorie restriction diets is for weight loss. Clinically caloric restriction is often used to reduce obesity levels, and to treat or manage illnesses that are associated with increased rates of obesity, for example cardiovascular disease, type 2 diabetes and metabolic syndrome. Small studies have shown that hypocaloric diets can reduce inflammation in people without ME/CFS, which may improve some ME/CFS symptoms since raised inflammation markers and neuroinflammation are caused by ME/CFS. Reducing inflammation may reduce pain.
Exercise and Activity
Building muscle tissue is going to be your weight loss superpower. The more muscle mass you have, the faster your metabolism and the better you are at fat burning. It can be tempting to diet as soon as you feel you are strong enough, but actually my guidance would be to focus on eating a maintenance level of calories (e.g. You’ll need to be able to resistance train at an intensity that will stimulate muscle growth and it may take some time until you can do this. All bodies are different, so don’t necessarily think that a lack of experience puts you at a disadvantage. While I was building up my exercise tolerance I focussed on eating enough protein and eating to match my intake, if not, more than my intake (surplus). Over the course of about 6 months I gained a further 7 pounds (½ stone) and I was the heaviest I have ever been. Once you have given yourself a good amount of time to build muscle mass (minimum 6 months), you can use a calorie deficit to lose body fat. I would normally take 10%-15% off daily energy expenditure. This means that if you were burning approximately 2000 calories per day, you could start dieting at a deficit of 200-300 calories, i.e. The goal is to lose weight on the most amount of calories, not the least. The whole process took approximately 18-20 months and I had to be healthy enough to do it! I’m now at a place where I am happy maintaining what I have achieved. I have recently changed my training and began my journey learning Functional Patterns with Brendan Turner.
Additional Tips for Managing Weight and CFS
Some people with CFS may gain weight, or find it more difficult to lose excess weight, due to increased appetite and reduced physical activity levels. If this is the case for you, try to limit your intake of fatty and sugary snacks and drinks. Aim to eat according to the Australian guidelines described above. Be mindful that weight loss may also take a bit longer if you have CFS. Keep a food and symptom diary - tracking what you eat and how you feel is a great way to discover any relationship between your diet and your energy levels. Make changes slowly - it can be tempting to plan radical changes to your diet if it will help you feel better. Rather than changing several things at once - or eliminating whole food groups altogether - try making small, sustainable changes. Be patient - don’t expect dietary changes to impact your CFS symptoms overnight. These things take time, so be patient with yourself and persevere. Eat smaller meals more often - people with CFS frequently don’t feel hungry or are too tired to bother with eating.
Read also: Weight Gain, Hair Loss, Fatigue: What Could Be the Cause?