Why you should eat more bread (if it’s the right loaf)

Awesome news for carb lovers: cutting out bread may not cut the kilos. Some breads prove a magic bullet for blasting body fat.

A new study shows eating high fibre rye breads actually helped weight loss. Pictures: Thinkstock

Rejoice, bread lovers! Your favourite food, usually blamed for piling on the pounds, may actually help with weight loss — provided that it is the right variety. For a study published in the journal Clinical Nutrition, Swedish researchers showed that substituting regular wheat with high-fibre rye-based bread and cereals proved to be a magic bullet for blasting weight and body fat in a group of mostly middle-aged men and women.

Rikard Landberg, a professor of food and health at Chalmers University of Technology in Sweden and the lead author on the study, asked half of the 242 overweight participants to eat a bowl of rye-based breakfast cereal, four to six slices of rye crisp bread (think Ryvita) and two to two and a half slices of soft rye bread every day, while the others ate refined wheat versions with the same total calorie intakes. The key difference, Landberg says, was that the rye group “got about 30g of fibre a day compared with just 8g obtained by the others” and his goal was to determine how the switch affected their ability to shed pounds.

Fat-blasting fibre feats

After 12 weeks the high-fibre group had lost an average 1kg more than the refined wheat group, an amount entirely attributable to extra fat loss.

“Previous epidemiological studies have clearly shown that high-fibre foods in general are good for long-term weight management,” Landberg says, “but our study was the largest to look specifically at how a high-fibre grain in the diet can affect body weight and body fat, and we have shown fibre to have an important and beneficial effect.”

Quite how fibre works to blast body fat is intriguing. Some fibres are known to increase in volume, becoming gel-like in the stomach and boosting the feeling of fullness. This satiety effect means that if we eat enough fibre we are generally less inclined to snack and binge because hunger pangs diminish. “We also know that fibre entraps some of the energy, or calories we consume from food, particularly fat, and makes it unavailable for absorption by the body,” Landberg says. “We have shown in some of our other studies that more fat from food is excreted when rye fibre is consumed.”

Then there’s the way fibre works with the microbiome — the vast ecosystem of yeasts, bacteria, fungi and viruses that inhabit the digestive system.

The secret is in choosing the right bread. Picture: iStock

Go with your gut

“Fibre really gets to work in our gut,” says Dr Adele Costabile, a researcher in fibre and nutrition at the University of Roehampton, London. “It has multiple mechanisms of influencing weight loss, working in different parts of our gastrointestinal tract.” Studies have shown how a low-fibre diet causes the kind of chronic gut inflammation that interferes with the way we digest and use calories from our food, causing our bodies to store more excess calories as fat. Increasing fibre intake triggers gut bacteria to produce metabolites that affect how full we feel and even boost metabolism.

A high-fibre diet can further suppress appetite by sending signals from the gut to the brain to tell it that you’re feeling full. “We don’t yet have the full picture, but in our study we could see that certain bacteria were present to a greater extent after participants ate the higher-fibre foods,” Costabile says. “Those bacteria are known to produce short-chain fatty acids, such as butyrate, which is a signalling molecule for increased satiety.”

For all these benefits, our fibre-eating record remains abysmal. According to the most recent update of the National Diet and Nutrition Survey, our intake is “below the government recommendations for all age groups”, with just 9 per cent of adults reaching the recommended goal of 30g a day. “Most adults get only 18g of fibre a day, which is 60 per cent of what they should be getting,” Costabile says. Children aged 5-11 need 25g of fibre a day, but only 10 per cent get that much, whereas a lowly 4 per cent of 11 to 18-year-olds meet their 25g daily requirement.

All rise for rye

It’s tantalising to think that we could ward off creeping weight gain by increasing our intake. Landberg says that he has no intention of easing up on his habit of snacking on as many rye crispbreads as he can. “So far I have not gained weight, so I’ll carry on,” he says.

His advice is that we all find our fibre-fillers. “In the UK you eat far below the common recommendations for daily fibre,” he says. “If intake could be increased, I am sure it would have a beneficial effect on body weight and health.”

THE GOLDEN RULES

1. What’s the best source of fibre?

Fibre is the part of plant-based food that mostly passes through the stomach and small intestine without being digested. “There are different types – soluble fibres, such as beta-glucans in oats dissolve in water, whereas insoluble fibres, such as cellulose found in fruits, vegetables, whole grains, nuts and seeds, do not,” Costabile says. “But all types have benefits and we need a variety of fibre sources in our diets.”

Nuts and seeds also provide vital fibre. Picture: iStock

Fruit and vegetables are the obvious sources, although Costabile says that “under 25 per cent of adults and 15 per cent of children across the UK are eating the recommended five a day”. Wholegrain bread, porridge oats, figs, nuts and seeds, and peas, beans and lentils are good fibre providers.

2. How do we know we are getting enough?

Your aim (as an adult) is 30g a day and you can start by checking food labels and tallying fibre counts using a tracker. “It is not as difficult as it used to be to track fibre, and food labels now provide information about the fibre content of products,” Costabile says. “The more sophisticated nutrition and diet apps also offer fibre tracking.” Try the Nutracheck app and the Ryvita FibreFit app to keep tabs on your daily intake.

3. Can’t I just take a fibre supplement?

A fibre supplement may provide some short-term benefits. “Recent studies suggest a decline in gut microbiome diversity is very common in overweight people, and a supplement containing inulin, oligofructose and other prebiotic fibres can help to restore it,” Costabile says. “In one of our studies we showed improvements in microbiome diversity after just four weeks of taking a fibre supplement.”

But she says that it is no long-term panacea. Most supplements provide one or two fibre sources and for maximum benefits diversity is key. “The key element in maintaining gut microbiome diversity is to include a variety of dietary fibres from different foods in your daily diet,” Costabile says.

4. Eat whole fruit and veg, not smoothies and soups

Thomas Barber, an associate professor and honorary consultant endocrinologist at the University of Warwick who has published papers on fibre, says that our dietary habits over the past two decades have done much to add to the decline of our fibre intake. Eating more processed foods obviously hasn’t helped, but dietary trends such as pulverising fruit and vegetables into smoothies and juices or blending soups until smooth are not beneficial either. They provide fibre to our bodies in a different, less effective format from that in a whole fruit or vegetable. “Consuming food as close to its natural state is the best way to get more fibre,” Barber says. “In general, that means minimally processed food, and whole fruit and vegetables.”

5. Don’t cut carbs completely

The trend for complete carb avoidance has had a big impact on fibre intake. “Many carb-containing foods are rich in fibre, so by cutting out things like bread and cereals we are potentially losing a major source of it in our diets,” Barber says. “The key is to look for wholegrain versions of these products and to avoid the highly processed variety.”

Choose rye, spelt and buckwheat or breads with added seeds or grains, such as bulgur, pearl barley, quinoa, teff, buckwheat, brown rice and oatmeal.

6. Can’t tolerate high fibre?

If large doses of fermentable fibres are consumed, the bacteria in the colon produce gases to break them down, which can cause IBS-type symptoms. “Overdoing it on fibre may cause some discomfort,” Costabile says. “Because fibre makes bowel movements bigger and bulkier and can also promote gas formation, an excessive intake or a sudden increase can affect the digestive system.”

Eating smaller, more frequent fibre-rich meals can help to ease the strain on the colon. You can overdo it, and more than 70g a day is too much for most people to tolerate, she says.

The Times