Irish Visitors Click HereLow carb diets & constipation
How Low Carb diets developed
Low carbohydrate (carb) diets started to become fashionable in the 1920's when it was "the in thing" to be thin.
These 'diets' developed like any other fashion: people looked for new ways to shed weight and leaving out bread and potatoes seemed easier than banishing the focus of a meal, like meat or poultry. Starchy foods were thought of as cheap, stodgy and fattening because they were filling. People lost weight purely by cutting the amounts they ate, though there is some credence in the 'insulin control' effect of cutting starchy carbohydrates or sugars which raise blood sugars and can increase the desire for more.
In recent times, this craze has intensified and instead of reducing starch alone, people have cut all carbohydrates, including fruits and vegetables. This has led to some would say potentially hazardous situation of low-fibre intake which can cause constipation.
Examples of high and low carb foods.
All plants contain carbohydrate. However, starchy foods such as potatoes and pasta have more grams of carbohydrate than many other food, due to their density.
High carbohydrate foods yield about 50-60g carb per portion:
- Potatoes
- Pasta
- Bread
- Rice
- Cereals
Medium carbohydrate foods yield around 10-20g carb per portion:
- Milk
- Yoghurt
- Fruit salad
- Bananas
- Nectarine
- Mango
- Melon
- Oranges
- Peaches
- Parsnips
Low carbohydrate foods yield less than 6g per portion:
- strawberries
- raspberries
- most vegetables with few exceptions such as potatoes and cauliflower
What do carbohydrates do in the body
Carbohydrate is simply where you get your energy and starchy carbs are the quickest way to get fast energy. This goes straight to the muscles and liver, which can hold about 1,600 calories. Carbs also hold water, which is useful and when carbs are reduced, the body effectively loses 'weight' by drying out and losing muscle stores. This is not fat.
How does a low carb diet affect the digestive system/ cause constipation
The body must have fibre to help get rid of waste. All vegetable and fruit matter has fibre. The odd meal without much fibre is not a problem - it is the relentlessness of the low-carb diet that can cause problems. (see text in red above which points to website's with evidence) Day after day of protein and little fibre slows the digestive system markedly and this can lead to constipation.
What is the recommended amount of carbohydrates in the diet?
The amount of carbohydrate depends on your weight and activity level. Generally allow 3/4g carbohydrate per day, per kilogram of your body weight for a normal/sedentary lifestyle, 1g per kg per day if you are quite active and 1.5g per day if you are extremely active and do a lot of heavy muscular work or bodybuilding.
The importance of fibre in low-carb diets
If you have chosen low-carb because you do not have an energetic lifestyle this is not a bad reason as it is the safest and most effective way to reduce calories. However, choose wisely. We only need about 21g fibre a day, but this can be quite difficult to eat when your diet is severely carbohydrate -reduced
Examples of low-carb fibre products
These foods are high in fibre but low in carbohydrate and calories.
- Strawberries
- Blackcurrants
- Oranges
- Paw-paw
- Pear
- Ratatouille
- Carrots
Higher calorie, high carb and high fibre foods
- baked beans
- broad beans
- kidney beans
- dried fruit
- coconut
- rice
- figs
- peanuts and chestnuts
Foods with NO fibre:
- Oils
- butter
- yoghurt
- milk
- cheese
- cream
- fish
- meat
- poultry
What are the latest trends to follow
The Atkins diet, which at certain stages, recommends reducing carbohydrates to a low 10-20g a day and saw many converts suffer constipation, has sunk from popularity. Its place has been taken by the Glycaemic index trend, an old system rather than a diet, which ranks carbohydrates according to their impact on blood sugar levels.
This is not a bad trend to follow: however, my simple advice will always be to reduce starch and fill the diet with non-starchy, high fibre carbohydrates like salads and fresh vegetables with low-sugar fruits and three daily servings of dairy food.
- View interactive animations of how the digestive system works »
- Find out what the symptoms of constipation are »
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