A low carbohydrate diet can be incredibly nutritious; however, some nutrient goals may be harder to achieve, to consistently attain these goals we recommend planning meals in advance.
Variety is the number one way to achieve your nutrition goals and is something often neglected by people trying to lose weight or improve their health. It is very easy to have the same meals on high rotation, just to keep life simple, but by varying your protein sources and vegetable options, as well as including some nuts, seeds, and dairy (if tolerated) you will be much more likely to hit your various recommended dietary intake (RDI) and therefore be much less likely to suffer any deficiencies.
One reason there are a few nutrients that need to be discussed is the amount of fortification found in processed foods such as breads and cereals.
The main nutrients that are more likely to be deficient in a low carb diet are thiamine, folate, vitamin C, magnesium, iron, vitamin D, vitamin E, calcium, and fibre.
Let’s discuss each one in turn:
Thiamine is also known as B1 and is important for energy production, growth, development as well as brain and nervous system function. Thiamine works with other B vitamins, so a depletion of one can cause others to function less effectively in the body. Like other B vitamins, thiamine is water-soluble which means it isn’t stored in your body, so you should consume it on a regular basis.
Fortunately, thiamine is naturally found in a variety of foods. Thiamine is found predominantly in cereal foods (due to fortification), but there are still plenty of low carb sources.
The Recommended Daily Intake (RDI) is 1.1 milligrams (mg) for women and 1.2 mg for men.
- Pork loin: 100g uncooked = 0.7 mg Thiamine
- Macadamia nuts: 30g = 0.3 mg Thiamine
- Flaxseed: 1 tablespoon = 0.2 mg Thiamine
- Asparagus: 1 cup = 0.2 mg Thiamine
- Chicken livers: 100g = 0.3 mg Thiamine
- Salmon: 100 g cooked = 0.3 mg Thiamine
- Pecans: 30g = 0.2 mg Thiamine
- Peanuts: 30g = 0.2 mg Thiamine
Many non-starchy vegetables provide .06 mg to .09 mg thiamine per cup so your intake of these will also count towards your daily intake.
Folate
Folate, also known as B9 is a B-complex vitamin that is essential to produce DNA and RNA, so it’s needed for normal cell replication and division.
Folate is possibly best known for preventing neural tube defects, a type of birth defect. In Australia, many foods, particularly breads are fortified with folic acid to help reduce the likelihood of neural tube defects. This is great – but those of us trying to follow a low carb lifestyle often miss out on the benefits of food fortification. For women planning or likely to conceive, taking a supplement that includes at least 600 mcg of folic acid is recommended. Folic acid is the form of folate found in supplements and fortified foods. Folic acid is more bioavailable, meaning that the body is better able to use it.
Adult women and men should consume approx. 400 micrograms (mcg) of folate per day (pregnant women need 600 mcg).
- Chicken livers: 100g = 578 mcg folate
- Sunflower seeds: 100g = 225 mcg folate
- Avocado: One half avocado = 80 mcg folate
- Asparagus: 1 cup = 70 mcg folate
- Romaine lettuce: 1 cup = 64 mcg folate
- Spinach: 1 cup raw = 58 mcg folate
- Broccoli: 1 cup chopped = 57 mcg folate
- Brussels sprouts: 0.5 cup cooked = 47 mcg folate
Vitamin C
Probably the most well-known vitamin, vitamin C performs many functions in the body. This vitamin is essential for brain neurotransmitters to function properly, and it protects our cells from damage. Vitamin C is also necessary for building connective tissue and promotes resistance to infection. Vitamin C can also enhance non-haem iron absorption.
Many people associate vitamin C with fruit and assume they will struggle to get enough on a low carb diet, however on a wholefood, low carb diet containing plenty of non-starchy vegetables it shouldn’t really be a problem.
Vitamin C is easily degraded during storage and cooking so to maintain the vitamin C content of your food, store it in the fridge and try not to overcook it (who likes over cooked vegetables anyway?)
The RDI for vitamin C for both men and women is 45 mg
Low-Carb Sources of vitamin C
- Capsicum: 0.5 cup raw = 60-95 mg (depending on colour!)
- Broccoli: 1 cup chopped, raw = 81 mg
- Green capsicum: 0.5 cup raw = 60 mg
- Brussels sprouts: 0.5 cup raw = 48 mg
- Cauliflower: 1 cup = 46 mg
- Cabbage: 1 cup chopped, raw = 33 mg
- Strawberries: 1 cup sliced = 89 mg
Other good sources of vitamin C include spinach and other leafy greens, raspberries and green beans. Almost all fruits and vegetables contain some vitamin C.
As you can see it’s easy to achieve the RDI without any fruit, but adding a few berries is a sure way to get an extra hit!
Magnesium
Magnesium plays a wide range of roles in the body, supporting protein synthesis, bone development and maintenance, DNA synthesis, and cell function. Many of us don’t get enough magnesium, in fact, 1 in 3 adults in Australia don’t get enough magnesium every day.
People who are especially at risk of not getting enough magnesium are people with conditions such as Crohn’s disease and coeliac disease, people with type 2 diabetes, older people and people who drink a lot of alcohol.
Adult women should consume approximately 320 mg and men should consume approximately 400 mg of magnesium each day.
Low-Carb Sources of Magnesium
- Pumpkin seeds: 30g = 156 mg magnesium
- Almonds:30 g = 80 mg magnesium
- Spinach: 1/2 cup cooked = 78 mg magnesium
- Avocado: 1 cup cubed = 44 mg magnesium
- Chia seeds: 30 g = 111 mg magnesium
Other good sources of magnesium include dark chocolate, most green vegetables, fatty fish (eg. salmon) and yoghurt.
Magnesium is one of the few supplements we suggest many patients take. There are a range of different types and the type we recommend will likely depend on your personal need – ask your regular practitioner which form of magnesium is best for you but do try and fill up your diet with plenty of the options mentioned above.
Iron
Iron is extremely important to our health. Without it, our cells cannot get oxygen. Iron is responsible for haemoglobin formation, improves the quality of our blood, and increases resistance to disease and stress. And yet, especially for women of reproductive age, iron deficiency is common, even when consuming a low carb diet. Many women consume more white meat (eg. chicken or fish) rather than red meat and hitting the daily target is quite hard. Iron deficiency needs to be treated with supplementation or an iron infusion – then iron stores can be maintained with dietary sources.
Adult women of childbearing age should consume 18 mg of iron each day. Men and women over childbearing age should consume 8 mg of iron each day.
Low-Carb Sources of Iron
- Chicken liver: 100g raw = 10 mg
- Clams: 100g = 14 mg
- Beef liver: 100g raw = 5.5 mg
- Beef/lamb: 100g raw = 2.1 mg
- Kangaroo: 100g = 3.4mg
- Chicken thigh: 100g = 1.1mg
- Oysters/mussels: 100 g 3.9 mg
- Asparagus: 1 cup = just under 3 mg
- Spinach: 1 cup raw = about 1 mg
Vitamin D, Vitamin E, and Calcium
Deficiencies in these nutrients aren’t specific to low-carb diets. Many people consuming a typical Australian diet don’t get enough vitamin D, vitamin E, or calcium so they are worth mentioning.
Vitamin D
Vitamin D is necessary for the maintenance and balance of calcium and phosphorus in the body. This micronutrient also plays a role in other systemic functions in the body.
Getting enough vitamin D can be difficult through food sources alone and regular sun exposure is the best source of vitamin D. Vitamin D deficiency is becoming more common, both in Australia and overseas. This may be since people are spending less time outside due to work and lifestyle, and people are also more responsible about wearing sunscreen, particularly in Australia due to many years of education around excessive sun exposure!
The recommended intake of vitamin D is 600 IU daily for adult men and women. Low-carb sources of vitamin D include salmon, tuna, eggs, yoghurt, and liver and the most important – sunlight!
Vitamin E
Vitamin E is a fat-soluble vitamin that functions as an antioxidant. There are eight different forms of the nutrient, which is one of the reasons it’s best to get vitamin E from foods. The recommended intake of vitamin E is 15 mg daily for adult men and women. Low-carb sources of vitamin E include most nuts and seeds (especially sunflower seeds), greens, avocado, capsicum, and prawns.
Calcium
Calcium plays many roles in the body, but it’s best known for the development of bone mass and maintenance of bone strength. It’s also vital to the functioning of our muscles and nerves. The recommended intake of calcium is 1,000 mg daily for adult men and women. However, women over the age of 50 should consume 1,200 mg per day. Low-carb sources of calcium include dairy products, sardines, canned salmon, tofu, and dark green vegetables.
Fibre
Achieving fibre goals is one of the most mentioned issues with a low carb diet. The current RDI of fibre is 30g of fibre each day for men and 25 mg for women. The truth is that very few Australians eating a standard Australian diet are meeting these fibre targets.
If eating a well-planned low carb diet, you are likely to be able to meet these goals by increasing your vegetable intake with many leafy green vegetables contributing a significant amount of fibre. Adequate fibre, both soluble and insoluble, can be easily derived from vegetables, some fruit, nuts, and seeds without added wholegrains.
Remember to enjoy a variety of foods across your week. The greater your food variety the more likely you are to hit your micronutrient goals and improve your gut health as well!
If you need additional advice to meet these goals book in to see me and we can do some nutritional analysis. If you are interested in testing your nutrient status or have some underlying health problems you’d like investigated, talk to one of our GPs.