Prevention focuses on improving sanitation of water and food sources.

Treatment focuses on addressing the central components of intestinal inflammation, bacterial overgrowth and nutritional supplementation.

The treatment or management of cachexia depends on the underlying causes, the general prognosis and other person related factors. Reversible causes, underlying diseases and contributing factors are treated if possible and acceptable. A growing body of evidence supports the efficacy of (HMB) as a treatment for reducing, or even reversing, the loss of muscle mass, muscle function, and muscle strength that occurs in hypercatabolic disease states such as cachexia; consequently, it is recommended that both the prevention and treatment of muscle wasting conditions include supplementation with HMB, regular resistance exercise, and consumption of a high-protein diet. Progestins such as megestrol acetate are a treatment option in refractory cachexia with anorexia as a major symptom.

Cachexia occurs less frequently now in HIV/AIDS than in the past due to the advent of highly active antiretroviral therapy (HAART). Treatment involving different combinations for cancer cachexia is recommended in Europe, as a combination of nutrition, medication and non-drug-treatment may be more effective than monotherapy. Non-drug therapies which have been shown to be effective in cancer induced cachexia include nutritional counselling, psychotherapeutic interventions, and physical training. Anabolic-androgenic steroids like oxandrolone may be beneficial in cancer cachexia but their use is recommended for maximal 2 weeks since a longer duration of treatment increases the burden from side effects.

Other drugs that have been used or are being investigated in cachexia therapy, but which lack conclusive evidence of efficacy or safety, and are not generally recommended include:

- Thalidomide and cytokine antagonists

- Cannabinoids

- Omega-3 fatty acids, including eicosapentaenoic acid (EPA)

- Non-steroidal anti-inflammatory drugs

- Prokinetics

- Ghrelin and ghrelin receptor agonist

- Anabolic catabolic transforming agents such as MT-102

- Selective androgen receptor modulators

- Cyproheptadine

- Hydrazine

Medical marijuana has been allowed for the treatment of cachexia in some US states, such as Illinois, Maryland, Delaware, Nevada, Michigan, Washington, Oregon, California, Colorado, New Mexico, Arizona, Vermont, New Jersey, Rhode Island, Maine, and New York Hawaii and Connecticut.

There is insufficient evidence to support the use of oral fish oil for the management of cachexia associated with advanced cancer.

There are multiple large-field, multi-country research initiatives focusing on strategies to prevent and treat EE.

- The MAL-ED project

- The Alive and Thrive nutrition project

- The Sanitation, Hygiene and Infant Nutrition Efficacy (SHINE) Trial (ClinicalTrials.gov identifier: NCT01824940)

- The WASH Benefits Study

Early and aggressive treatment is required to control the disorder. Diuretic medications help rid the body of excess fluid. ACE inhibitor medications (like Captopril and others) and non-steroidal anti-inflammatory drugs (like indomethacin) are used to slow the spilling of protein (albumin) in the urine. Antibiotics may be needed to control infections. Patients may also take iron supplements, potassium chloride, thyroxine and other vitamins to replenish what minerals the kidneys have leaked out.

Most patients will undergo regular and frequent albumin infusion (often daily) to replace what kidneys have lost. Infusions are performed via IV so a central venous catheter will need to be surgically inserted into patients chest or groin.

Dietary modifications may include the restriction of sodium and use of dietary supplements as appropriate for the nature and extent of malnutrition. Fluids may be restricted to help control swelling.

Many patients have a gastrostomy tube (g-tube) inserted for medication and/or feeds. Some patients develop oral aversions and will use the tube for all feeds. Other patients eat well and only use the tube for medicine or supplemental feeds. The tube is also useful for patients needing to drink large amounts of fluids around the time of transplant.

Patient will require removal of the kidneys (one at the time or both), dialysis, and ultimately a kidney transplant.

Only limited treatment options exist for patients with clinical cancer cachexia. Current strategy is to improve appetite by using appetite stimulants to ensure adequate intake of nutrients. Pharmacological interventions with appetite stimulants, nutrient supplementation, 5-HT antagonists and Cox-2 inhibitor have been used to treat cancer cachexia, but with limited effect.

Studies using a more calorie-dense (1.5 kcals/ml) and higher protein supplementation have suggested at least weight stabilization can be achieved, although improvements in lean body mass have not been observed in these studies.

Therapeutic strategies have been based on either blocking cytokines synthesis or their action. Thalidomide has been demonstrated to suppress TNF-alpha production in monocytes "in vitro" and to normalize elevated TNF-alpha levels "in vivo". A randomized, placebo-controlled trial in patients with cancer cachexia showed the drug was well tolerated and effective at attenuating loss of weight and lean body mass (LBM) in patients with advanced pancreatic cancer. An improvement in the LBM and improved quality of life were also observed in a randomized, double-blind trial using a protein and energy-dense, omega-3 fatty acids-enriched oral supplement, provided its consumption was equal or superior to 2.2 g of eicosapentaenoic acid per day. It is also through decreasing TNF-alpha production. However, data arising from a large, multicenter, double-blind, placebo-controlled trial indicate EPA administration alone is not successful in the treatment of weight loss in patients with advanced gastrointestinal or lung cancer.

Peripheral muscle proteolysis, as it occurs in cancer cachexia, serves to mobilize amino acids required for the synthesis of liver and tumor protein. Therefore, the administration of exogenous amino acids may theoretically serve as a protein-sparing metabolic fuel by providing substrates for both muscle metabolism and gluconeogenesis. Studies have demonstrated dietary supplementation with a specific combination of high protein, leucine and fish oil improves muscle function and daily activity and the immune response in cachectic tumor-bearing mice. In addition, β-hydroxy-β-methyl butirate derived from leucine catabolism used as a supplement in tumor-bearing rats prevents cachexia by modifying NF-κB expression.

A phase-2 study involving the administration of antioxidants, pharmaconutritional support, progestin (megestrol acetate and medroxyprogesterone acetate), and anticyclooxygenase-2 drugs, showed efficacy and safety in the treatment of patients with advanced cancer of different sites suffering cachexia. These data reinforce the use of the multitargeted therapies (nutritional supplementation, appetite stimulants, and physical activity regimen) in the treatment of cancer cachexia.

New studies indicate NSAIDS, like Sulindac, were found to significantly decrease cachexia.

Also studies have shown branched-chain amino acids can return the metabolism of a cachectic patient from catabolic-losing weight- to anabolic- increasing muscle, in over 55% of patients. Branched-chain amino acids consist primarily of leucine and valine. In a research paper published by the Indian J of Palliat Care, the effects the findings concluded that bcaa's interfere with brain serotonergic activity and inhibit the overexpression of critical muscular proteolytic pathways. The potential role of branched-chain amino acids as antianorexia and anticachexia agents was proposed many years ago, but experimental studies and clinical trials have since tested their ability to stimulate food intake and counteract muscle wasting in anorectic, weight-losing patients. In experimental models of cancer cachexia, BCAAs were able to induce a significant suppression in the loss of body weight, producing a significant increase in skeletal muscle wet weight[30] as well as in muscle performance and total daily activity.

The conditionally essential amino acid glutamine has been used as a component of oral supplementation to reverse cachexia in patients with advanced cancer or HIV/AIDS.

Once diagnosed, tropical sprue can be treated by a course of the antibiotic tetracycline or sulphamethoxazole/trimethoprim (co-trimoxazole) for 3 to 6 months.

Supplementation of vitamins B and folic acid improves appetite and leads to a gain in weight.

Treatment is primarily through diet. Dietary fiber and fat can be increased and fluid intake, especially fruit juice intake, decreased. With these considerations, the patient should consume a normal balanced diet to avoid malnutrition or growth restriction. Medications such as loperamide should not be used. Studies have shown that certain probiotic preparations such as "Lactobacillus rhamnosus" (a bacterium) and "Saccharomyces boulardii" (a yeast) may be effective at reducing symptoms.

, there are no approved medications for the treatment of sarcopenia; however, β-hydroxy β-methylbutyrate (HMB), a metabolite of leucine which is sold as a dietary supplement, has demonstrated efficacy in preventing the loss of muscle mass in individuals with sarcopenia. A growing body of evidence supports the efficacy of HMB as a treatment for reducing, or even reversing, the loss of muscle mass, muscle function, and muscle strength in hypercatabolic disease states such as cancer cachexia; consequently, it is recommended that both the prevention and treatment of sarcopenia and muscle wasting in general include supplementation with HMB, regular resistance exercise, and consumption of a high-protein diet. Based upon a meta-analysis in 2015, HMB supplementation appears to be useful as a treatment for preserving lean muscle mass in older adults. More research is needed to determine the precise effects of HMB on muscle strength and function in this age group.

DHEA and human growth hormone have been shown to have little to no effect in this setting. Growth hormone increases muscle protein synthesis and increases muscle mass, but does not lead to gains in strength and function in most studies. This, and the similar lack of efficacy of its effector insulin-like growth factor 1 (IGF-1), may be due to local resistance to IGF-1 in aging muscle, resulting from inflammation and other age changes.

Testosterone or other anabolic steroids have also been investigated for treatment of sarcopenia, and seem to have some positive effects on muscle strength and mass, but cause several side effects and raise concerns of prostate cancer in men and virilization in women. Additionally, recent studies suggest testosterone treatments may induce adverse cardiovascular events. Other approved medications under investigation as possible treatments for sarcopenia include ghrelin, vitamin D, angiotensin converting enzyme inhibitors, and eicosapentaenoic acid.

In order to avoid problems, the person must be rehabilitated with small but frequent rations, given every two to four hours. During one week, the diet, hyperglucidic, is gradually enriched in protein as well as essential elements: sweet milk with mineral salts and vitamins. The diet may include lactases - so that children who have developed lactose intolerance can ingest dairy products - and antibiotics - to compensate for immunodeficiency. After two to three weeks, the milk is replaced by boiled cereals fortified with minerals and vitamins until its mass is at least 80% of normal weight. Traditional food can then be reintroduced. The child is considered healed when his mass reaches 85% of normal.

Treatment is variable depending on individuals. Some treatments work extremely well with some patients and not at all with others. Some treatments include Therapy with thiamine and vitamin B complex. Alcohol consumption should be stopped. Some patients survive, but with residual brain damage and dementia. Others remain in comas that eventually lead to death. Nutritional counseling is also recommended. Treatment is often similar to those administered for Wenicke-Korsakoff syndrome or for alcoholism.

Type A has 21% mortality rate and an 81% long-term disability rate. Type B has a 0% mortality rate and a 19% long-term disability rate.

Preventive measures for visitors to tropical areas where the condition exists include steps to reduce the likelihood of gastroenteritis. These may comprise using only bottled water for drinking, brushing teeth, and washing food, and avoiding fruits washed with tap water (or consuming only peeled fruits, such as bananas and oranges). Basic sanitation is necessary to reduce fecal-oral contamination and the impact of environmental enteropathy in the developing world.

Treatment is directed largely towards management of underlying cause:

- Replacement of nutrients, electrolytes and fluid may be necessary. In severe deficiency, hospital admission may be required for nutritional support and detailed advice from dietitians. Use of enteral nutrition by naso-gastric or other feeding tubes may be able to provide sufficient nutritional supplementation. Tube placement may also be done by percutaneous endoscopic gastrostomy, or surgical jejunostomy. In patients whose intestinal absorptive surface is severely limited from disease or surgery, long term total parenteral nutrition may be needed.

- Pancreatic enzymes are supplemented orally in pancreatic insufficiency.

- Dietary modification is important in some conditions:

- Gluten-free diet in coeliac disease.

- Lactose avoidance in lactose intolerance.

- Antibiotic therapy to treat Small Bowel Bacterial overgrowth.

- Cholestyramine or other bile acid sequestrants will help reducing diarrhoea in bile acid malabsorption.

Treatment with antibiotics such as amoxicillin or cefdinir improve the response and survival rate of severely malnourished children to an outpatient treatment plan which provided therapeutic food. This confirms the recommendation, "In addition to the provision of RUTF [ready-to-use therapeutic food], children need to receive a short course of basic oral medication to treat infections." contained in "Community-based management of severe acute malnutrition, A Joint Statement by the World Health Organization, the World Food Programme, the United Nations System Standing Committee on Nutrition and the United Nations Children’s Fund."

The World Health Organization (WHO) recommends rehydrating a severely undernourished child who has diarrhea relatively slowly. The preferred method is with fluids by mouth using a drink called oral rehydration solution (ORS). The oral rehydration solution is both slightly sweet and slightly salty and the one recommended in those with severe undernutrition should have half the usual sodium and greater potassium. Fluids by nasogastric tube may be use in those who do not drink. Intravenous fluids are recommended only in those who have significant dehydration due to their potential complications. These complications include congestive heart failure. Over time, ORS developed into ORT, or oral rehydration therapy, which focused on increasing fluids by supplying salts, carbohydrates, and water. This switch from type of fluid to amount of fluid was crucial in order to prevent dehydration from diarrhea.

Breast feeding and eating should resume as soon as possible. Drinks such as soft drinks, fruit juices, or sweetened teas are not recommended as they contain too much sugar and may worsen diarrhea. Broad spectrum antibiotics are recommended in all severely undernourished children with diarrhea requiring admission to hospital.

To prevent dehydration readily available fluids, preferably with a modest amount of sugars and salt such as vegetable broth or salted rice water, may be used. The drinking of additional clean water is also recommended. Once dehydration develops oral rehydration solutions are preferred. As much of these drinks as the person wants can be given, unless there are signs of swelling. If vomiting occurs, fluids can be paused for 5–10 minutes and then restarting more slowly. Vomiting rarely prevents rehydration as fluid are still absorbed and the vomiting rarely last long. A severely malnourished child with what appears to be dehydration but who has not had diarrhea should be treated as if they have an infection.

For babies a dropper or syringe without the needle can be used to put small amounts of fluid into the mouth; for children under 2, a teaspoon every one to two minutes; and for older children and adults, frequent sips directly from a cup. After the first two hours, rehydration should be continued at the same or slower rate, determined by how much fluid the child wants and any ongoing diarrheal loses. After the first two hours of rehydration it is recommended that to alternate between rehydration and food.

In 2003, WHO and UNICEF recommended a reduced-osmolarity ORS which still treats dehydration but also reduced stool volume and vomiting. Reduced-osmolarity ORS is the current standard ORS with reasonably wide availability. For general use, one packet of ORS (glucose sugar, salt, potassium chloride, and trisodium citrate) is added to one liter of water; however, for malnourished children it is recommended that one packet of ORS be added to two liters of water along with an extra 50 grams of sucrose sugar and some stock potassium solution.

Malnourished children have an excess of body sodium. Recommendations for home remedies agree with one liter of water (34 oz.) and 6 teaspoons sugar and disagree regarding whether it is then one teaspoon of salt added or only 1/2, with perhaps most sources recommending 1/2 teaspoon of added salt to one liter water.

Antiretrovirals and anabolic steroids have been used to treat HIV wasting syndrome. Additionally, an increase in protein-rich foods such as peanut butter, eggs, and cheese can assist in controlling the loss of muscle mass.

Treating malnutrition, mostly through fortifying foods with micronutrients (vitamins and minerals), improves lives at a lower cost and shorter time than other forms of aid, according to the World Bank. The Copenhagen Consensus, which look at a variety of development proposals, ranked micronutrient supplements as number one.

In those with diarrhea, once an initial four-hour rehydration period is completed, zinc supplementation is recommended. Daily zinc increases the chances of reducing the severity and duration of the diarrhea, and continuing with daily zinc for ten to fourteen days makes diarrhea less likely recur in the next two to three months.

In addition, malnourished children need both potassium and magnesium. This can be obtained by following the above recommendations for the dehydrated child to continue eating within two to three hours of starting rehydration, and including foods rich in potassium as above. Low blood potassium is worsened when base (as in Ringer's/Hartmann's) is given to treat acidosis without simultaneously providing potassium. As above, available home products such as salted and unsalted cereal water, salted and unsalted vegetable broth can be given early during the course of a child's diarrhea along with continued eating. Vitamin A, potassium, magnesium, and zinc should be added with other vitamins and minerals if available.

For a malnourished child with diarrhea from any cause, this should include foods rich in potassium such as bananas, green coconut water, and unsweetened fresh fruit juice.

Untreated, the disease has a mortality rate upwards of 90%. Cats treated in the early stages can have a recovery rate of 80–90%. Left untreated, the cats usually die from severe malnutrition or complications from liver failure. Treatment usually involves aggressive feeding through one of several methods.

Cats can have a feeding tube inserted by a veterinarian so that the owner can feed the cat a liquid diet several times a day. They can also be force-fed through the mouth with a syringe. If the cat stops vomiting and regains its appetite, it can be fed in a food dish normally. The key is aggressive feeding so the body stops converting fat in the liver. The cat liver has a high regeneration rate and the disease will eventually reverse assuming that irreparable damage has not been done to the liver.

The best method to combat feline hepatic lipidosis is prevention and early detection. Obesity increases the chances of onset. In addition, if a cat stops eating for 1–2 days, it should be taken to a vet immediately. The longer the disease goes untreated, the higher the mortality rate.

Congenital nephrotic syndrome can be successfully controlled with early diagnosis and aggressive treatment including albumin infusions, nephrectomy, medications and ultimately a kidney transplant. Most children live fairly normal life post-transplant but will spend significant time hospitalised pre-transplant and have numerous surgeries to facilitate treatment.

Due to the protein (albumin) losses many patients have reduced muscle tone and may experience delays in certain physical milestones such as sitting, crawling and walking. Similarly many patients experience growth delays due to protein loss. Delays vary from mild to significant but most patients experience growth spurts once they receive their transplanted kidney. Physical therapy may be useful for the child to strengthen muscle tone.

Undiagnosed cases are often fatal in the first year due to blood clots, infections or other complications.

Measures have been taken to reduce child malnutrition. Studies for the World Bank found that, from 1970 to 2000, the number of malnourished children decreased by 20 percent in developing countries. Iodine supplement trials in pregnant women have been shown to reduce offspring deaths during infancy and early childhood by 29 percent. However, universal salt iodization has largely replaced this intervention.

The Progresa program in Mexico combined conditional cash transfers with nutritional education and micronutrient-fortified food supplements; this resulted in a 10 percent reduction the prevalence of stunting in children 12–36 months old. Milk fortified with zinc and iron reduced the incidence of diarrhea by 18 percent in a study in India.

However, diagnosis can be difficult due to the comprehensive measurements used in research that are not always practical in healthcare settings. Hand grip strength alone has also been advocated as a clinical marker of sarcopenia that is simple and cost effective and has good predictive power, although it does not provide comprehensive information.

Exercise remains the intervention of choice for sarcopenia but translation of findings into clinical practice is challenging. The type, duration and intensity of exercise are variable between studies, so an ‘off the shelf’ exercise prescription for sarcopenia remains an aspiration.

The role of nutrition in preventing and treating sarcopenia is less clear. Large, well-designed studies of nutrition particularly in combination with exercise are needed, ideally across healthcare settings. For now, basing nutritional guidance on the evidence available from the wider health context is probably the best approach with little contention in the goals of replacing vitamin D where deficient, and ensuring an adequate intake of calories and protein, although there is debate about whether currently recommended protein intake levels are optimal.

There is no known cure for microcephaly. Treatment is symptomatic and supportive.

Available treatment falls into two modalities: treating infections and boosting the immune system.

Prevention of Pneumocystis pneumonia using trimethoprim/sulfamethoxazole is useful in those who are immunocompromised. In the early 1950s Immunoglobulin(Ig) was used by doctors to treat patients with primary immunodeficiency through intramuscular injection. Ig replacement therapy are infusions that can be either subcutaneous or intravenously administrated, resulting in higher Ig levels for about three to four weeks, although this varies with each patient.

Most symptoms will improve quickly if deficiencies are treated early. Memory disorder may be permanent.

In patients suspected of WE, thiamine treatment should be started immediately. Blood should be immediately taken to test for thiamine, other vitamins and minerals levels. Following this an immediate intravenous or intramuscular dose of thiamine should be administered two or three times daily. Thiamine administration is usually continued until clinical improvement ceases.

Considering the diversity of possible causes and several surprising symptomatologic presentations, and because there is low assumed risk of toxicity of thiamine, because the therapeutic response is often dramatic from the first day, some qualified authors indicate parenteral thiamine if WE is suspected, both as a resource for diagnosis and treatment. The diagnosis is highly supported by the response to parenteral thiamine, but is not sufficient to be excluded by the lack of it. Parenteral thiamine administration is associated with a very small risk of anaphylaxis.

Alcohol abusers may have poor dietary intakes of several vitamins, and impaired thiamine absorption, metabolism, and storage; they may thus require higher doses.

If glucose is given, such as in hypoglycaemic alcoholics, thiamine must be given concurrently. If this is not done, the glucose will rapidly consume the remaining thiamine reserves, exacerbating this condition.

The observation of edema in MR, and also the finding of inflation and macrophages in necropsied tissues, has led to successful administration of antiinflammatories.

Other nutritional abnormalities should also be looked for, as they may be exacerbating the disease. In particular, magnesium, a cofactor of transketolase which may induce or aggravate the disease.

Other supplements may also be needed, including: cobalamin, ascorbic acid, folic acid, nicotinamide, zinc, phosphorus (dicalcium phosphate) and in some cases taurine, especially suitable when there cardiocirculatory impairment.

Patient-guided nutrition is suggested. In patients with Wernicke-Korsakoff syndrome, even higher doses of parenteral thiamine are recommended. Concurrent toxic effects of alcohol should also be considered.

Bacterial overgrowth is usually treated with a course of antibiotics although whether antibiotics should be a first line treatment is a matter of debate. Some experts recommend probiotics as first line therapy with antibiotics being reserved as a second line treatment for more severe cases of SIBO. Prokinetic drugs are other options but research in humans is limited. A variety of antibiotics, including tetracycline, amoxicillin-clavulanate, fluoroquinolones, metronidazole, neomycin, cephalexin, trimethoprim-sulfamethoxazole, and nitazoxanide have been used; however, the best evidence is for the use of rifaximin.

A course of one week of antibiotics is usually sufficient to treat the condition. However, if the condition recurs, antibiotics can be given in a cyclical fashion in order to prevent tolerance. For example, antibiotics may be given for a week, followed by three weeks off antibiotics, followed by another week of treatment. Alternatively, the choice of antibiotic used can be cycled.

The condition that predisposed the patient to bacterial overgrowth should also be treated. For example, if the bacterial overgrowth is caused by chronic pancreatitis, the patient should be treated with coated pancreatic enzyme supplements.

Probiotics are bacterial preparations that alter the bacterial flora in the bowel to cause a beneficial effect. Animal research has demonstrated that probiotics have barrier enhancing, antibacterial, immune modulating and anti-inflammatory effects which may have a positive effect in the management of SIBO in humans. "Lactobacillus casei" has been found to be effective in improving breath hydrogen scores after 6 weeks of treatment presumably by suppressing levels of a small intestinal bacterial overgrowth of fermenting bacteria. The multi-strain preparation VSL#3 was found to be effective in suppressing SIBO. "Lactobacillus plantarum", "Lactobacillus acidophilus", and "Lactobacillus casei" have all demonstrated effectiveness in the treatment and management of SIBO. Conversely, "Lactobacillus fermentum" and "Saccharomyces boulardii" have been found to be ineffective. A combination of "Lactobacillus plantarum" and "Lactobacillus rhamnosus" has been found to be effective in suppressing bacterial overgrowth of abnormal gas producing organisms in the small intestine.

Probiotics are superior to antibiotics in the treatment of SIBO. A combination of probiotic strains has been found to produce better results than therapy with the antibiotic drug metronidazole and probiotics have been found to be effective in treating and preventing secondary lactase deficiency and small intestinal bacteria overgrowth in individuals suffering from post-infectious irritable bowel syndrome. Probiotics taken in uncomplicated cases of SIBO can usually result in the individual becoming symptom free. Probiotic therapy may need to be taken continuously to prevent the return of overgrowth of gas producing bacteria. A study by the probiotic yogurt producer Nestlé found that probiotic yogurt may also be effective in treating SIBO with evidence of reduced inflammation after 4 weeks of treatment.

An elemental diet taken for two weeks is an alternative to antibiotics for eliminating SIBO. An elemental diet works via providing nutrition for the individual while depriving the bacteria of a food source. Additional treatment options include the use of prokinetic drugs such as 5-HT4 receptor agonists or motilin agonists to extend the SIBO free period after treatment with an elemental diet or antibiotics. A diet void of certain foods that feed the bacteria can help alleviate the symptoms. For example, if the symptoms are caused by bacterial overgrowth feeding on indigestible carbohydrate rich foods, following a FODMAP restriction diet may help.

Medical treatment can directly or indirectly cause weight loss, impairing treatment effectiveness and recovery that can lead to further weight loss in a vicious cycle.

Many patients will be in pain and have a loss of appetite after surgery. Part of the body's response to surgery is to direct energy to wound healing, which increases the body's overall energy requirements. Surgery affects nutritional status indirectly, particularly during the recovery period, as it can interfere with wound healing and other aspects of recovery. Surgery directly affects nutritional status if a procedure permanently alters the digestive system. Enteral nutrition (tube feeding) is often needed. However a policy of 'nil by mouth' for all gastrointestinal surgery has not been shown to benefit, with some suggestion it might hinder recovery.

Early post-operative nutrition is a part of Enhanced Recovery After Surgery protocols. These protocols also include carbohydrate loading in the 24 hours before surgery, but earlier nutritional interventions have not been shown to have a significant impact.

Some medications can cause weight loss, while others can cause weight gain.