Fruits and Vegetables
Estimated reading time: 5 minutes
Next lesson: Macronutrients: Fat
Lesson 8: Fruits and Vegetables
What are fruits and vegetables?
Vegetables are the edible stems, leaves, and roots of a plant.
Fruits are the seed-containing parts of a plant.
Fruits and vegetables contain nutrients like vitamins and minerals that your body uses to maintain vital function and to repel and fight disease.
These vitamins and minerals are referred to as micronutrients because your body needs them in small amounts (whereas macronutrients like carbohydrates are needed in larger amounts).
Fun fact #1: Coffee beans are the seeds of the coffee fruit which resemble cherries.
Fun fact #2: While we often think of mushrooms as vegetables, they are in fact actually fungi (which is a pretty fun fact, right? Anyone?)
Benefits of fruits and vegetables
Most vegetables tend to be ‘low GI’ which stands for ‘glycemic index’. This is a measure of how much your blood sugar levels change after eating. The lower the number, the less your blood sugar levels will spike, which helps with a more gradual release of energy and also satiety.
Simple carbohydrates are usually in the higher ranges of GI. This includes fruits as they contain high amounts of fructose, although they do also come with fibre and other nutrients that are essential for your body. This makes them better options than sugary drinks or junk foods when you do choose to have simple carbohydrates.
Diets that are high in fruit and vegetable intake are associated with greater health and is linked with less:
Cardiovascular disease
Cancer
High blood cholesterol
High blood pressure
Diabetes
Obesity
Asthma
Osteoporosis
Variety and ‘food colours’ are important.
There are a lot of functions and processes that micronutrients (vitamins and minerals) provide for your body. Certain fruits and vegetables offer different micronutrients so eating a variety of them can help ensure you are having enough for your body to function optimally.
We recommend aiming for 5 food colours a day as a guide.
List of vitamins and minerals:
Vitamin A: immune function and wound healing, red blood cell development, synthesising proteins
Vitamin B5: maintaining skin health, synthesising cholesterol + sex hormones + neurotransmitters
Vitamin B6: nervous and immune system function, forming neurotransmitters and sex hormones
Vitamin B7: DNA replication, forming enzymes used in gluconeogenesis + energy production + fat synthesis
Vitamin B9: Forming new proteins, red blood cell formation and circulation, fetal development
Vitamin B12: Forming and maintaining healthy nerve cells and red blood cells, DNA synthesis
Vitamin C: Antioxidant, helps iron absorption, building collagen
Vitamin D: Immune system function, regulating glucose tolerance, cell differentiation
Vitamin E: Antioxidant, cell signalling, expression of immune and inflammatory cells
Vitamin K: Blood clotting, amino acid metabolism, cell signalling,
Calcium: Transmitting nerve impulses, muscle contraction, hormone secretion, forming teeth and bones
Iron: Forming red blood cells and blood vessels, producing energy, building proteins and enzymes
Magnesium: carbohydrate and fat metabolism, DNA and protein synthesis, cell migration and wound healing
Potassium: Maintaining an electrochemical gradient across cell membranes, enzyme activity
Green fruits and vegetables
These fruits and vegetables (particularly dark and leafy greens) are densely packed with nutrients and have a large profile of vitamins and minerals that include:
Vitamins: A, B9, E, and K
Minerals: Calcium, Iron, Magnesium
You can find most greens in vegetables like kale, silverbeet, asparagus, brussel sprouts, peas, and parsley.
A diet that has green in it will tend to help with:
Immunity
Red blood cell production
Protein synthesis
Managing inflammation
Hormone secretion
Energy production
Carbohydrate and fat metabolism
Cell signalling
Red and orange fruits and vegetables
These fruits and vegetables tend to have:
Vitamins: A, C
Minerals: Potassium
Red fruits and vegetables include capsicums, tomatoes, red cabbage, red onion, and raspberries.
Orange fruits and vegetables include corn, pumpkin, carrots, oranges, and pineapples.
A diet that has red and orange in it will tend to help with:
Immunity
Antioxidants
Building collagen (a structural protein)
Keeping cells healthy
White fruits and vegetables
These fruits and vegetables tend to have:
Vitamins: B5 and 6
Minerals: Magnesium, Potassium
White fruits and vegetables include onions, apples, parsnips, coconuts, and garlic.
A diet with white in it will help with:
Maintaining healthy skin
Synthesizing cholesterol, hormones, and neurotransmitters
DNA replication
Carbohydrate and fat metabolism
How much fruit and vegetables you need
Purple fruits and vegetables
These fruits and vegetables tend to have:
Vitamins: B5 & 7
Minerals: Chromium, Iron, Magnesium, Potassium
Purple fruits and vegetables include beetroot, eggplant, and blueberries.
A diet with purple in it will help with:
Maintaining healthy skin
Synthesising cholesterol, hormones, and neurotransmitters
Carbohydrates and fat metabolism
Producing energy
Cell signalling and health
Older Food Pyramid Model
An updated food pyramid
Traditionally, carbohydrates like bread, pasta, rice, and grains have been at the base of the food pyramid. This was largely due to how cost effective it was to produce these types of carbohydrates for large numbers of people.
While these processed carbohydrates provide a good source of energy (carbohydrate being our bodies preferred source of energy), they don’t provide the same amount micronutrients that fruit and vegetables do.
As research has developed more in recent times, you will likely now see more fruit and vegetables in the base of the food pyramid as they can provide the body with carbohydrates (kumara, potatoes, etc) but also provide many of the essential micronutrients that bread and pasta don’t.
How many fruits and vegetables should you have?
A good starting point is to aim for:
6-8 servings of vegetables a day
1-3 servings of fruit a day
Within the above, aim for 1 serving of each food colour (green, red, orange, white, purple).
If you’re training intensely or an athlete, you may consider having more fruit around workouts to help fuel performance.
Serving sizes:
A single serving of fruit is a cupped handful.
A single serving of vegetables is a closed fist.
Tips to getting enough micronutrients
Aim for whole food sources (as always)
Add leafy greens into smoothies for a quick addition
Stir fries or soups are simple ways to use a variety of vegetables at once
Add fruit to your oats
Visit your local farmers market for more affordable fruit and vegetables
If you’re a plant based eater then it’s important to supplement vitamin B12. This is not readily available in plant form and is needed to make new cells in the body.
Note:
Supplements should be used to supplement a diet made up mostly of minimally processed whole foods. Don’t rely on supplements to plug gaps in a faulty diet.
Getting your fruit and vegetables in the from juice bars is still good for getting in some nutrients, but note it’s often stripped of much of the good stuff (like fibre), leaving behind high amounts of sugar.