The composition of a balanced diet is a hotly debated issue. As this book is being written the main excitement among slimmers concerns low-carbohydrate/high-protein diets; these appear to miraculously shift the body’s chemistry so that unwanted fat melts away. This is an attractive idea seized upon by millions, but it has a drawback. Eating low-carbohydrate foods means restricting the consumption of fibre, and this can lead to the most common form of gut complaint: constipation. If you read Chapter 5, about diverticulitis and the various health problems involving constipation, you will see why this common condition should be avoided. There are ways to get around problems presented by low-carbohydrate diets. Laxatives are the most popular solution – but they can become habit forming and do not provide the benefit of minerals and vitamins found in a well-balanced diet.
High-protein diets are only one reason the problem of constipation is accelerating. The modern Western diet invites trouble by being based on foods that are low in fibre and high in refined sugar and saturated fats – all of which are bad for the gut. As a result, every day more of us are afflicted by indigestion, gastric ulcers, flatulence, diverticulitis and constipation, leading to serious bowel disease, including cancer. Both soluble and insoluble fibre help reduce this risk. Eating brown rice, bran and nuts provides insoluble fibre. Fresh fruits and vegetables, brown bread, oats and pulses are rich sources of soluble fibre. Dried fruits and whole grains provide both. When planning a balanced diet, include sources of both types of fibre.
There are significant differences in the two types of fibre. Insoluble fibre has no known health benefit other than providing bulk to discourage constipation. Like the soluble form, it consists of complex and indigestible carbohydrates. To a limited extent, insoluble fibre helps sustain the normal bacterial flora of the gut, which also add to the weight and bulk of the waste – or stool – as it works its way through the lower bowel. Without bulk, the muscular walls of the intestine get flabby and relaxed, and fail to be efficient.
Soluble fibre, on the other hand, gives up its form and dissolves in the watery environment of the digestive system. Consider what happens when you prepare porridge. As the oats cook and pieces of grain swell, the simmering water or milk begins to thicken and become viscous due to the release of soluble fibre. In the gut, the same molecules that thicken the porridge can absorb various substances (such as bile) during digestion, preventing their transfer into the bloodstream. Considerable research evidence suggests that this nutritionally inert substance not only supports good gut health, but also helps reduce blood cholesterol levels and prevents sharp fluctuations in blood sugar.
The right foods help prevent cancer. In 1997, a major research report by the World Cancer Research Fund, Food, Nutrition and the Prevention of Cancer, announced that what you eat dramatically affects your cancer risk. One recommendation stands out from all others: individuals can significantly decrease their risk of developing certain cancers by increasing their intake of fruits and vegetables. Based on this report, the British food writer Oliver Gillie produced Food for Life, Preventing Cancer through Healthy Diet in 1998. His advice is:
• Enjoy a plant-based diet rich in its variety of fruits, vegetables and pulses. Minimize your intake of starchy staple foods.
• Eat 400–800 grams (15–30 ounces) of fruits and non-root or tuberous vegetables a day – every day of the year (this works out to be five or more servings).
• Eat 600–800 grams (20–30 ounces) of mixed cereals and root or tuberous vegetables and plantains.
• Choose minimally processed foods and restrict consumption of refined sugar.
• If meat is your source of protein, give it a low priority; 80 grams (3 ounces) a day is adequate for adults. Preferred meats are fish, poultry and meat from non-domesticated animals (venison and hare from reputable sources are excellent foods).
• Limit your intake of saturated fat. (Fat is part of a healthy diet. Tip your fat intake towards unsaturated fats like those in oils, nuts, olives and avocados.)
• Alcohol is ‘not recommended’. (Keep your intake well within safe limits. See here.)
• Avoid charred foods. (Skip the blackened barbecued steak, especially the charred fat.)
• Limit your salt intake and avoid salted and preserved foods.
Since publication of the report by the World Cancer Research Fund, medical and governmental authorities have flooded the news media with information about the importance of eating fruit and vegetables; five portions a day has been recommended as a healthy dietary goal for everyone. There is scant evidence, however, that the general public has taken the message on board. Women, and particularly younger women, appear to be more receptive to the message than other demographic groups, but most men still look upon fruit and vegetables as uninteresting food. Of even greater concern, recent studies of children’s diets show they fall far short of ideal.
In her personal story, Marguerite Patten writes about her experience with irritable bowel syndrome. Like many others suffering from serious illnesses of the digestive system, probiotics helped her regain control over her body and maintain good health. We see references to probiotics in the health media, and new lines of probiotic foods and supplements appear in the shops almost monthly. But questions still remain: what are probiotics; how do they work; and what do they have to do with food? The answers are all about bacteria.
According to Lennart Cedgårt, MD, writing for www.positivehealth.com, dysbiosis is a major cause of intestinal illness (‘dys’ means faulty, and ‘bios’ means life and growth). Put simply, the faulty growth of gut bacteria causes problems. ‘Pro’ biosis is needed to correct faulty bacterial growth and support a healthy environment within the gut.
The presence of bacteria in the intestines was mentioned in Chapter 2. These organisms contribute to the absorption of minerals, proteins and vitamins from the gut; they break down (ferment) fibrous food residue and combine with water and digestive sludge to form the bulk (stool or faeces) eventually evacuated from the body. Different types of bacteria live and multiply in the gut. Under normal conditions they exist in a happy balance, but this can be altered radically by stress, medication, eating tainted food and a poor diet.
Sometimes the mere introduction of a new strain of healthy bacteria can cause a major upset, something experienced by many travellers. After the first day in a foreign location there may be a noticeable change in the gut, perhaps signalled by rumbling and flatulence, and sometimes something more extreme. A day later, the problem is gone. Food eaten can came from the best and cleanest hotels and restaurants, but the problem is difficult to avoid. While you are enjoying the tastes and textures of delicious new foods, your stomach is encountering a new strain of one or more of the normal bacteria inhabiting your gut. It takes time for things to adjust. Here are two pieces of good advice: go easy on food and drink for the first 24 hours after you arrive at your destination, and always carry lactic bacteria (probiotics) supplements with you. Starting probiotics before your arrival can minimize the risk of feeling unwell.
Probiotics contain healthy (lactic) bacteria known to convert