The Ins and Outs of a Plant Based Diet Post-Bariatric?
Can I get enough protein from a plant-based diet after bariatric surgery?
Plant based diets are growing in popularity with more people being more environmentally conscious, certain cultural and ethical beliefs and such a wide range of plant-based products available to us in the supermarket. Generally, this means increasing our plant foods… think fruits, veggies, wholegrains, legumes, nuts and seeds and reducing our intake of animal foods such as meats, eggs and dairy. As we know these animal foods are valuable sources of protein in the diet... so is a plant-based diet suitable after bariatric surgery? After having bariatric surgery, we can only eat very small amounts …. usually about ½ a cup of food (however this depends which stage post-surgery you are at). So, is it possible to meet our nutritional needs with only small amounts of plant-based proteins?
What are Plant-Based Diets?
There are various types of plant-based diets some of the most common types include…
Vegan Diet - Excludes all animal products i.e. meat, fish, or poultry and animal by-products such as honey, dairy and eggs.
Vegetarian Diet - Does not include any meat, fish, or poultry - however does include eggs, dairy foods and honey.
Pescatarian Diet - Excludes all types of meat except for fish, shellfish, and seafood. Some may include eggs and dairy foods and some people choose not to.
Flexitarian Diet - This is a more flexible plant-based diet built on the foundation of plants, whilst still including small amounts of meat, fish, eggs, and dairy as desired. Therefore, is more flexible and less restrictive than other common plant-based diets.
No matter what type of plant-based diet or the reason for this particular diet there are various nutritional considerations that may be important post bariatric surgery.
Protein requirements
After bariatric surgery one of the major nutrients of focus is protein. Our protein requirements are quite high because we are recovering from surgery. Protein assists our wound healing and helps maintain muscle mass… in our weight loss journey we certainly do not want to be losing muscle! Most people should be getting a minimum of 60g a day however this will vary depending on the individual and what your dietitian has recommended.
Protein powder is essential after bariatric surgery as we CANNOT meet our protein requirements when only consuming minimal amounts of food post-surgery. Generally, we want to aim for 2-3 scoops of protein powder per day. Your dietitian will be able to recommend how much and what type is suitable for you. Some commonly used protein powders include Tasteless Protein Powder, Boomers, BeneProtein and Peptipro. These are not suitable for a strict vegan diet as they are made using some animal products therefore you will need a suitable plant-based protein powder. These can often be expensive and hard to find so it is best to discuss with your dietitian a protein powder that is suitable for you. Protein powder maybe required required for up to 12 months post-surgery however this time may increase on a plant-based diet as plant based proteins are usually required in slightly greater quantities than animal proteins therefore may take longer to meet your requirement with food based sources.
We also want to make sure all of our meals are predominantly protein based - aim for at least 80% of your meals to be protein rich foods this includes meat, chicken, fish, tofu, tempeh, legumes, eggs, dairy, nuts and seeds. Consuming protein is the first priority over carbohydrates and fats after surgery.
Other nutrients at risk
If you are following a strict plant-based or what we call a vegan diet there are other nutrients you may be at higher risk of missing out on including calcium, iron, Vitamin B12 and zinc. Some of these nutrients are already at high risk of deficiency post bariatric surgery as we cannot absorb these effectively. This is why it is important to keep up your vitamins – we want to be taking specialised Bariatric vitamin supplements every day.
How to meet our nutrition requirements on a plant-based diet
Protein
It is important to consume plenty of protein rich plant foods to make sure you are meeting the protein requirements your dietitian has recommended. Plant-based proteins are often not as complete as animal-based proteins, meaning they do not contain all of the essential amino acids needed by the body. Therefore, if you are avoiding meat, fish and eggs we want to aim to eat a range of different plant proteins so we make sure we are getting a variety of all of the essential amino acids.
Plant-based sources of protein:
Tofu
Tempeh
Legumes - baked beans, chickpeas, lentils,kidney beans, black beans.
Nuts and seeds i.e. walnuts, almonds, peanuts, brazil nuts, cashews and nut butters.
Soy milk and yoghurts
Soy beans
Vegetarian sources:
Dairy milks, yoghurt and cheese.
Eggs
How much protein in a serve? 1 serve = 8 -10g protein
Plant based food Serve size
Chicken or beef mince (comparator) ¼ cup
Tuna (if pescatarian) 60g small tin
Tofu ½ cup
Peanut Butter 1-2 tablespoons
Nuts ¼ cup or 1 handful
Legumes ½ cup
Eggs 1 egg
Optifast 100mL
As you can see we need slightly more quantity of plant based foods to get 1 serve (8-10g) of protein - this may be difficult if you are only able to consume very small amounts i.e. less than ½ cup. In this case you may need to work closely with your dietitian to make sure you are supplementing with additional protein powder.
Dairy and Dairy Alternatives
There is many different types of plant milks available to us nowadays and these are not all the same in terms of their nutritional profile! Soy milk is a plant milk made from soy-beans and is the most nutritionally similar to dairy milk as it contains similar amounts of protein and many are fortified with calcium and additional vitamins and minerals. Therefore, this is a suitable alternative to meet protein requirements post bariatric surgery.
1 serve = 5g Protein
Vegetarian/ plant-based food Serve size
Cows milk 1/2 cup
Soy milk 1/2 cup
Yoghurt 100g
Custard ½ cup
Cottage or ricotta cheese 2 Tablespoons
Hard cheese 1 slice
High protein yoghurt i.e. YoPro or Chobani ¼ cup
Soy yoghurt ½ cup
Calcium
Calcium is an important mineral to support healthy bones and teeth. Calcium is predominantly found in dairy milk, yoghurt and cheese. Therefore, when choosing milk alternatives we want to aim for something that is fortified with calcium aiming for ~120mg/100mL. Other plant-based sources of calcium include almonds, dark leafy greens (e.g. spinach, broccoli, bok choy), legumes, tahini and chia seeds.
Iron
Iron is an important nutrient needed for healthy blood cells, transporting oxygen around our body, producing energy and optimal immune function. Iron from plant sources is absorbed less efficiently in the body than that from animal sources. Therefore, if following a plant-based diet it is important you are getting plenty of plant-based sources of iron and optimising this absorption. Plant based sources of iron include wholegrains, nuts, dried fruits, green leafy vegetables, seeds, legumes and iron fortified cereals. To optimise absorption, we can pair these iron sources with Vitamin C rich foods such as citrus fruits (lemons & oranges), kiwi fruits, strawberries, green leafy vegetables, tomatoes and capsicums.
Vitamin B12
Vitamin B12 is a nutrient only found naturally in animal products including meat, fish, eggs and dairy. A vegan diet does not contain any B12 unless fortified in foods therefore you may need to consider a supplement or looking for fortified foods. This will not be a problem if taking Bariatric Multivitamins as these contain Vitamin B12 as absorption of this nutrient is impaired after surgery.
Zinc
Zinc is an important nutrient needed to support a healthy immune system and also assists in wound healing. Meat, fish and poultry are major sources of zinc in the diet therefore is generally a nutrient that may need extra attention on a plant-based diet. Other plant-based sources of zinc include nuts, seeds, legumes/beans, tempeh and wholegrains. If you are taking a Specialised Bariatric Vitamin this will contain zinc, as with B12, the absorption of zinc in the body is impaired after surgery.
The Verdict
In summary yes you can meet your nutrition requirements on a plant-based diet post bariatric surgery…. It is best, however, that you speak with your dietitian to make sure this is done properly and you are supplementing with the right type and amount of protein throughout your recovery. Not a fan of tofu, tempeh, legumes, beans and soy??? Maybe going completely plant-based is not for you as these are valuable sources of plant-based protein… However, there are various other ways you can adopt a more plant focused diet! This may be simply reducing your meat intake, adopting a pescatarian or even a flexitarian style of eating. Book in online with one of our Accredited Practising Dietitians at Ward Nutrition or phone to Book on 5301 6435 if you would like more practical advice and support. Telehealth or Face to face Consults Available.
Written by Accredited Practising Dietitian Claire Ward, Specialist Bariatric Dietitian at Ward Nutrition, Orange, Bathurst and Dubbo, NSW . Click here for more information on Ward Nutrition Bariatric Services.
References:
National Health and Medical Research Council, Nutrient Reference Values: https://www.nrv.gov.au/nutrients
J Clin Endocrinol Metab, November 2010, 95(11):4823– 4843
