Why you need to be getting 30 different plant foods per week
Why 30 plant foods?
One of the largest studies of human gut microbiota conducted in 2018, found that individuals who consumed 30+ different plant foods per week had greater diversity of gut microbes. Diversity within the gut is a very good thing! Gut microbiota (the community of micro-organisms themselves) influence many areas of human health from immunity to energy metabolism and appetite.
And it’s not just a ‘small thing in our guts’ - to give you some perspective there are 10x the amount of microbial cells in the human gut than there is in the entire human body - we are literally more bacteria than human. In fact, it weighs approx 2kgs! Bet you didn’t realise you were carrying around a couple of kilos of bacteria everyday!
While there is some genetic influence on our gut microbiota; the larger determinants are diet, drugs and body composition. Feeding your gut with lots of plant foods, and restricted amounts of highly processed foods (high in fat and sugar and low in fibre) help to increase the population of ‘good’ bacteria. Conversely, if we eat a diet high in processed foods which are high in fats, sugars and low in fibre we tend to increase the population of the ‘bad’ bacteria.
Feeding all these bacteria well helps our microbes to reduce inflammation throughout our body and gut and metabolise neurochemicals which are important in boosting serotonin levels (the feel good hormone).
We also know that particular drugs, food ingredients, antibiotics, and pesticides may have adverse effects on the gut microbiota. Lower bacterial diversity is found in individuals with inflammatory bowel disease, type 2 diabetes, coeliac disease, obesity and arterial stiffness.
What is so special about plant foods?
Plant foods contain fibre, which is the roughage or bulk parts of plants that our body cannot digest or absorb. These fibres are crucial in feeding the good bacteria in your gut. The consumption of fibre is also important for overall human health and lowering the risk of many chronic diseases; such as heart disease and some cancers. Despite this, many Aussies simply aren’t getting enough fibre in their diet - averaging just 20g per day. Women need to be aiming for 28g per day and men 38g per day - or MORE! Increasing your plant intake is a surefire way to increase your fibre intake - so win win!
While the old “5 and 2” a day is still an adequate suggestion, it does lack the diversity component which we now know is really important to gut health. I know that 30 different plant foods may initially sound like a LOT but it really isn’t! Trust me here. I am going to show you some examples of how you can increase plant diversity in your diet in a sec.
I would recommend you keep a list somewhere to keep track - even a note on your phone would do the trick. Once you know where you are at you can aim to increase your plant diversity in the coming weeks - until you are consistently hitting 30+ different plant foods per week. You don’t need to buy all sorts of weird and expensive ingredients; frozen and canned fruits and veggies count as do dried and canned legumes/beans. Let me know how many plant foods you hit in your first week of recording your intake.
What counts as plant foods - categories and examples (by no means an exhaustive list)
All fruits - lemon, apple, apricot, strawberries, oranges, kiwi fruit, grapes, pomegranate, cherries
All vegetables & herbs - potato, sweet potato, corn, carrot, lettuce, celery, pumpkin, avocado, cabbage, zucchini, bok choy, garlic, tomato, parsley, coriander
Nuts - walnuts, cashew, almonds, macadamia, peanuts, pecans, brazil nuts
Legumes - chickpeas, soybeans, split peas, cannellini beans, kidney beans, black beans, lentils
Grains - whole wheat, quinoa, barley, oats, rice, rye, sorghum
Seeds - pumpkin, flax, hemp, sesame, poppy, sunflower
Here are some examples of high and low diversity of meals throughout the day
Breakfast
High diversity
Wholemeal grain bread with spinach, tomato and mushroom, alongside an egg and even a small serve of baked beans = 11 different plants
Variety of frozen berries (blueberries, strawberries & raspberries) with some oats (as a porridge or muesli) with some chia seeds, flax seeds and nuts = 8+ different plants
Low diversity
Cornflakes with milk and banana = 2 different plants
Toast with vegemite = 1 plant food
Lunch
High diversity
Minestrone soup with wholemeal grain toast = 10 different plants
Tuna and brown rice salad = 10 different plants
Low diversity
Ham and cheese sandwich on white bread = 1 plant
Chicken tender wrap with lettuce and tomato = 3 different plants
Snacks
High diversity
Vita-weat 9 grain with avocado and tomato = 11 different plants
Fruit salad = 5 different plants
Yoghurt, mixed berries and nuts = 5 different plants
Low diversity
Muesli bar = 2 different plants
Apple = 1 plant
Yoghurt = 0 plants
Dinner
High diversity
Mixed salad (tomato, lettuce, avocado, onion, cucumber, carrot, alfalfa, capsicum) with chicken and wholegrain pasta = 9 different plants
Healthy spaghetti bolognese with wholegrain pasta = 10 different plants
Vegetarian tacos = 10 different plants
Low diversity
Steak with potato, peas and carrot = 3 different plants
Take away fish and chips = 1 plant
Always think about ways you can add in more variety with these tips too…
Try one new fruit and vegetable every week - look for what is in season to keep costs down. It doesn’t have to be fresh - look for frozen or canned varieties in fruits and veggies.
Try different varieties of grains - for example; swap to a wholemeal grain bread, try brown rice instead of jasmine, use quinoa instead of rice, add barley to soups.
Herbs also count so start using more herbs in cooking to enhance flavours instead of relying on excess salt and flavouring.
Start eating more legumes - go for at least one meat free meal a week and use different legumes. There are HEAPS of different varieties of canned beans around - so be sure to give them all a shot. Even better, use a 3 or 4-bean mix to really up the ante.
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References & further reading
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4191858/https://pubmed.ncbi.nlm.nih.gov/29566200/https://www.bmj.com/content/361/bmj.k2179https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5954204/