Recovering from anterior cruciate ligament (ACL) surgery is a long process that requires dedication and hard work. Many factors during recovery can contribute to weight gain, which is a common concern for patients. With the right diet and exercise program, it is possible to avoid packing on extra pounds. This article explores the reasons for weight gain after ACL surgery and provides tips to maintain your weight during recovery.
Reasons for Weight Gain After ACL Surgery
There are several reasons why patients may gain weight following ACL reconstruction surgery:
Inactivity
After surgery, patients are often unable to bear weight or walk normally for 4-6 weeks. This sudden decrease in activity and exercise can lead to weight gain. Without normal activity, your body burns fewer calories per day. If you continue to eat the same amount of calories, the unused calories get stored as fat.
Medications
Pain medications and anti-inflammatory drugs prescribed after surgery may cause fluid retention and increased appetite, both of which promote weight gain.
Muscle loss
The injured leg will lose muscle mass quickly after surgery due to disuse. Muscle tissue burns more calories than fat tissue, even at rest. Losing muscle decreases your daily calorie expenditure, making it easier to gain fat.
Comfort eating
Some patients overeat or indulge in comfort foods as a way to cope with stress and boredom during recovery. Emotional eating can easily lead to weight gain.
Depression
It is common to feel depressed after ACL surgery, as patients struggle with pain, loss of independence, and disruption to their normal routines. Depression is associated with poor appetite, overeating, and weight gain.
How Much Weight Gain Is Normal After ACL Surgery?
Most patients can expect to gain some weight during the first 6-8 weeks after ACL reconstruction surgery. Research indicates:
- Patients tend to gain an average of 5 pounds after surgery.
- Up to 20% of patients may gain 10 pounds or more.
- Weight gain peaks around 6-8 weeks post-op.
- Patients start losing the extra weight once they become more mobile and active in rehabilitation.
While a small amount of weight gain is common, more significant gains of 10+ pounds should not be considered normal or acceptable. With proper nutrition and exercise, major weight gain can be prevented.
Tips to Avoid Weight Gain After Surgery
Here are some tips to maintain your weight after ACL surgery:
Follow postoperative diet instructions
Your surgeon and dietitian may recommend a specific nutrition plan to promote healing after surgery. This may involve getting enough protein to prevent muscle loss, staying hydrated, and taking supplements like vitamin C and zinc. Follow any dietary guidelines from your care team.
Reduce overall calorie intake
Since your activity level is reduced, you need fewer calories per day. Cutting your calorie intake by 500-1000 calories daily can help offset weight gain.
Fill up on low calorie, nutrient-dense foods
Eat plenty of fruits, vegetables, lean proteins, whole grains, and low-fat dairy. These provide maximum nutritional value with minimal calories.
Limit sugar, salt, alcohol, fried foods, and refined carbs
Avoid empty calorie foods that can lead to quick weight gain but have low nutritional value.
Drink lots of water
Staying hydrated can reduce fluid retention and curb mindless snacking.
Take care when using crutches
Crutches require up to twice the energy expenditure as walking. Take frequent rest breaks when using crutches to avoid burning too many extra calories.
Start physical therapy as soon as allowed
Early rehab exercises will minimize muscle loss in your legs and get you moving again safely.
Modify upper body workouts
Once approved by your physical therapist, modify your usual upper body lifting routine to maintain fitness. Work closely with your PT.
Avoid emotional and stress eating
Find healthier ways to cope, like calling friends or meditating. Don’t use food to deal with stress or boredom.
Stay positive and motivated
Focus on your progress each week and remind yourself the restrictions are temporary. Enlist friends and family to support your weight goals.
Nutrition Tips for the First 6 Weeks After Surgery
What you eat matters most in the initial recovery period when you are immobilized and unable to exercise. Follow these diet tips:
Consume at least 1 gram protein/kg body weight daily
Getting enough protein helps maintain muscle and prevents excessive loss. Good protein sources include poultry, fish, eggs, dairy, beans, nuts, and protein shakes.
Take a fiber supplement like Benefiber
Pain medication and reduced activity can lead to constipation. Fiber improves regularity.
Drink nutritional shakes or smoothies
Liquid meal replacements provide protein, vitamins, and minerals when appetite is poor.
Choose healthy fats
Include omega-3 fatty acids from fish, nuts, seeds, avocados, and oils to reduce inflammation.
Eat your veggies
Aim for 5 servings of vegetables daily through smoothies, juices, and soups if chewing and digesting raw veggies is difficult.
Stay hydrated
Drink at least 64 ounces of fluids like water and herbal tea daily.
Allow occasional treats
Allow yourself a treat occasionally, like a favorite dessert, so you don’t feel deprived. Just keep portions small.
Listen to your body
Let your hunger guide you. Eat when hungry, stop when full.
Keep a food journal
Write down what you eat each day to stay accountable and notice problematic patterns.
Long-Term Strategies to Keep Weight Off
Once you complete rehabilitation and return to normal activity around 6 months post-op, it’s time to implement long-term diet and exercise strategies. Here are some tips:
Continue eating a balanced, nutritious diet
Stick with the healthy eating habits you formed during the first 6 weeks of recovery.
Exercise at least 30 minutes daily
Regular exercise helps maintain your weight. Walking, cycling, swimming and strength training are great options.
Lift weights 2-3 times per week
Strength training boosts your metabolism and helps regain muscle mass lost after surgery.
Weigh yourself weekly
Weigh in weekly to catch any creeping weight gain right away.
Develop an exercise routine you enjoy
You’ll be more likely to stick to workouts you find fun and interesting.
Join a gym or fitness classes
Having access to equipment, trainers, and group classes can provide motivation.
Set realistic weight goals
Aim to lose no more than 1-2 pounds per week for safe, sustainable weight loss.
Consider your calorie needs
Use online TDEE calculators to estimate your calorie needs for maintaining weight as your activity increases.
Join a support group
Connect online or in-person with others who have had ACL surgery to share experiences.
How to Exercise After ACL Surgery
Once your surgeon clears you to begin exercising, physical therapy helps rebuild strength and mobility in the injured leg. Later, you can progress to regular cardiovascular and strength training. Here are some tips for safe, effective workouts after ACL surgery:
Focus on range-of-motion initially
Begin by improving your knee’s range of motion with gentle exercises like heel slides and leg raises.
Progress slowly with strengthening
Start with isometric exercises, then bodyweight moves, before using weights. Build gradually.
Include balance exercises
Exercises on unstable surfaces like a BOSU ball retrain balance and knee proprioception.
Try aquatic therapy
The water provides gentle resistance great for early rehabbing stages.
Use cardio machines without impact
Cycling, swimming, and the elliptical allow cardio exercise without high joint forces.
Brace your knee if unstable
Wear a brace during exercise if you still have instability for safety.
Listen to your physical therapist
Follow your PT’s tailored program for optimal recovery.
Avoid twisting motions initially
Early on, avoid exercises requiring sudden pivoting, cutting or twisting.
Take a day off between strength sessions
Schedule rest days for recovery, especially after tough workouts.
Ice your knee after exercise
Icing reduces inflammation and relieves soreness to speed recovery.
Nutrition for Recovery After ACL Surgery
Eating the right nutrients and calories supports healing and recovery after ACL reconstruction surgery. Follow these nutrition tips:
Get enough protein
Aim for 0.5-0.7 grams of protein per pound of body weight daily from lean meat, eggs, dairy and plant sources.
Eat micronutrient-rich foods
Consume fruits, vegetables, whole grains for important vitamins and minerals.
Take vitamin C supplements
Vitamin C aids collagen production for ligament healing. Shoot for 1000 mg daily.
Stay hydrated
Drink at least 64 ounces of water daily to aid recovery.
Consume anti-inflammatory foods
Omega-3s from fish, nuts, healthy fats; ginger, turmeric, berries, tart cherries all reduce inflammation.
Avoid pro-inflammatory foods
Limit processed foods, sugary foods, refined carbs, alcohol and saturated fats as these worsen inflammation.
Time your nutrients
Eat a carbohydrate + protein meal or snack 30-60 minutes pre-workout and protein within 30 minutes post-workout.
Supplement collagen protein
Collagen peptides provide amino acids for connective tissue repair.
Weight Changes at Various Recovery Stages
Weight change during ACL surgery recovery isn’t linear. You can expect:
0-6 weeks:
- 5+ pound weight gain is common
- Muscle loss from immobility
- Can minimize gain through diet, nutrition supplements
2-3 months:
- Start losing some extra pounds as rehab progresses
- Begin retraining muscles
- Appetite and mobility increase
4-6 months:
- Should return to pre-surgery weight
- Regular exercise builds muscle
- Calorie needs increase with added activity
9-12 months:
- Fully recovered strength and fitness
- Can be more active than before injury
- Less risk of weight gain long-term if remain active
Tips to Prevent Muscle Loss After Surgery
It’s normal to lose some muscle after ACL surgery from disuse of your injured leg. To minimize muscle loss:
- Start physical therapy exercises as soon as allowed
- Practice leg raises and contractions of the quadriceps, hamstrings and glutes
- Try non-weight bearing exercises like wall sits and leg extensions
- Eat adequate protein to provide amino acids to maintain muscle
- Consider taking leucine or HMB, supplements shown to prevent muscle breakdown
- Have someone move your leg through range of motion if unable to do so yourself
- Use neuromuscular electrical stimulation to make muscles contract
- Do upper body and core workouts to keep moving
- Avoid long periods of inactivity
Preventing Arthritis and Re-Injury After ACL Surgery
Reconstructing and healing the ACL doesn’t guarantee it won’t tear again. About 5-10% of patients experience reinjury. Prevent future problems with these strategies:
- Complete physical therapy rehabilitation program
- Build muscles around knee for stability
- Work on balance and proprioception
- Allow 12+ months for graft to fully mature
- Wear a brace when returning to sports
- Start sports gradually and avoid pivoting too soon
- Have a physical therapist coach proper movement patterns
- Strengthen glutes and hips to share load on the knee
- Maintain a healthy body weight to reduce joint stress
- Consult your surgeon before returning fully to your sport
Arthritis is another potential long-term consequence, as the injury can damage the cartilage over time. You can reduce risks by:
- Avoiding second ACL injury through proper rehab
- Using safe biomechanics when exercising
- Strengthening muscles around the knee for stability
- Doing low-impact cardio like the elliptical or swimming
- Maintaining a healthy weight to avoid excess joint stresses
- Eating an anti-inflammatory diet with healthy fats and produce
- Quitting smoking to avoid degenerative changes
- Discussing supplements like glucosamine/chondroitin with your doctor
Conclusion
Gaining weight after ACL surgery is very common due to sudden inactivity, medication side effects, loss of muscle, and other factors. While a small amount of weight gain in the initial recovery period is to be expected, significant weight gain can be avoided through proper nutrition and slowly returning to exercise. Work closely with your surgeon, dietitian and physical therapist. With dedication to rehabilitation, it is possible to return to your pre-injury weight and fitness level within 6-12 months following surgery.