When people have heart surgery, what they eat afterward really matters for getting better. Researchers in China studied 197 patients after their heart surgeries and found that most weren’t eating enough protein during their first week of recovery. Protein is like the building blocks your body needs to heal wounds and get stronger. The study found that older patients and those with signs of inflammation were at higher risk of not getting enough nutrition. The good news? When doctors gave patients special nutritional drinks to boost their protein intake, it helped them recover faster and go home sooner. This research shows that paying attention to what heart surgery patients eat right after surgery could make a real difference in how quickly they heal.

The Quick Take

  • What they studied: Whether heart surgery patients were eating enough protein during their first week after surgery, and what factors made some patients more likely to have poor nutrition.
  • Who participated: 197 adults who had planned heart surgery at two hospitals in Shanghai, China. Researchers tracked what they ate and measured their nutrition levels on the day they arrived, and again 3 and 7 days after surgery.
  • Key finding: Most patients (96%) weren’t eating nearly enough protein after surgery—they averaged only about 0.58 grams per kilogram of body weight per day when doctors recommend at least 1.5 grams. Older patients and those with higher inflammation markers were more likely to have nutrition problems. When patients received special protein-rich nutritional drinks, it helped prevent malnutrition.
  • What it means for you: If you or a loved one is having heart surgery, ask your doctor about a nutrition plan that includes enough protein right from the start. This may help you recover faster and leave the hospital sooner. This is especially important for older adults or those with signs of infection or inflammation.

The Research Details

This was a real-world observation study, meaning researchers watched what actually happened to patients rather than randomly assigning them to different treatments. They enrolled 197 patients who were having planned heart surgery at two hospitals in Shanghai. Starting from the day patients arrived at the hospital through 7 days after surgery, researchers carefully tracked everything the patients ate using a method called 24-hour dietary recall, where patients describe all the food and drinks they consumed. The team also measured nutritional markers in the blood (like albumin, a protein) and used a scoring system called NRS-2002 to assess overall nutrition status.

The researchers collected information on admission day, then again on day 3 and day 7 after surgery. They also noted patient characteristics like age, weight, and blood test results that show inflammation levels. This approach allowed them to see patterns in who was at risk for poor nutrition and what factors helped or hurt recovery.

Understanding what happens with nutrition after heart surgery is important because the body is under stress and needs extra resources to heal. By observing real patients in actual hospital settings, researchers can identify practical problems and solutions that might not show up in controlled laboratory studies. This type of research helps doctors create better recovery plans.

This study has several strengths: it included a reasonable number of patients (197), tracked them carefully over a week, and measured nutrition in multiple ways. However, it was observational only, meaning we can see patterns but can’t prove that low protein directly caused longer hospital stays—other factors could be involved. The study was done in China, so results might be somewhat different in other countries with different hospital practices. The researchers used appropriate statistical methods to identify risk factors.

What the Results Show

The main finding was striking: patients averaged only 0.58 grams of protein per kilogram of body weight each day after surgery, which is less than 40% of the recommended amount of 1.5 grams per kilogram. Only 6 out of 197 patients (4.1%) actually met the protein target. This protein shortage was common across almost all patients, suggesting it’s a widespread problem in how heart surgery recovery is managed.

The researchers identified two main risk factors for malnutrition: advanced age and elevated white blood cell counts (a sign of inflammation or infection). For every year older a patient was, their risk of malnutrition increased slightly but consistently. Patients with higher white blood cell counts had significantly higher malnutrition risk. Importantly, patients who received oral nutritional supplements—special drinks designed to provide extra protein and calories—had better nutrition status and lower malnutrition risk.

Patients who developed malnutrition by day 7 after surgery stayed in the hospital significantly longer than those who maintained adequate nutrition. This suggests that nutrition status directly impacts recovery speed and hospital discharge timing.

Blood protein levels (albumin) dropped after surgery in most patients, which is expected as the body uses resources for healing. However, patients who received nutritional supplements showed better preservation of these protein levels. The study also showed that nutrition problems were particularly severe in older patients, suggesting this group needs extra attention and support with eating after surgery.

This research aligns with growing evidence that protein is especially important for surgical recovery, more so than just getting enough total calories. Previous studies have suggested that Enhanced Recovery After Surgery (ERAS) programs—which focus on early nutrition and movement—improve outcomes. This study provides real-world evidence supporting that protein specifically matters. The finding that nutritional supplements help is consistent with other surgical recovery research.

The study only followed patients for 7 days after surgery, so we don’t know long-term outcomes. It was observational, meaning we can see that malnutrition was associated with longer hospital stays, but we can’t prove malnutrition caused the longer stays—other health factors could be involved. The study was done in China, so hospital practices and patient populations might differ elsewhere. The researchers didn’t randomly assign patients to different nutrition plans, so we can’t be completely certain that supplements caused better outcomes, though the evidence is suggestive.

The Bottom Line

Heart surgery patients should aim for at least 1.5 grams of protein per kilogram of body weight daily starting immediately after surgery (moderate confidence). Older patients and those showing signs of infection or inflammation should receive special attention to ensure adequate protein intake, possibly through oral nutritional supplements (moderate confidence). Hospitals should implement nutrition screening and support programs as part of standard heart surgery recovery care (moderate confidence based on this and related research).

This research is most relevant for: people scheduled for heart surgery, their families and caregivers, cardiac surgeons and hospital teams, and older adults preparing for any major surgery. If you have a condition that affects eating or swallowing, discuss this specifically with your surgical team. This may be less directly applicable to people having minor procedures or those who can’t consume oral nutrition.

Nutrition support should begin immediately after surgery, ideally within the first 24 hours. Most benefits in terms of reducing malnutrition and hospital stay length appear within the first 7 days after surgery. Long-term benefits for overall recovery may take weeks to months to fully appear.

Want to Apply This Research?

  • After heart surgery, track daily protein intake in grams and compare it to your target (1.5 g per kg of body weight). For example, a 70 kg person should aim for 105 grams of protein daily. Log meals and use the app’s nutrition database to monitor progress toward this goal for the first 2 weeks post-surgery.
  • Set a daily reminder to consume a protein-rich food or supplement at each meal. If prescribed oral nutritional supplements, log when you drink them. Use the app to identify high-protein foods you enjoy so you’re more likely to eat them during recovery when appetite may be low.
  • Track protein intake daily for the first 7-14 days after surgery, then weekly for the next month. Monitor how you feel (energy level, wound healing, strength) and correlate it with protein intake. Share this data with your surgical team at follow-up appointments to adjust nutrition support if needed.

This research describes what happened in a specific group of heart surgery patients in China and should not be considered personal medical advice. Nutritional needs vary greatly between individuals based on age, weight, kidney function, and other health conditions. Before making changes to your diet or starting nutritional supplements, especially after surgery, consult with your surgeon, cardiologist, or a registered dietitian who knows your complete medical history. This information is educational and is not a substitute for professional medical guidance. If you have concerns about your nutrition after surgery, contact your healthcare provider immediately.