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Until now, we knew fibre filled you up, physically, which reduced hunger. But new evidence is showing us there's more to the story of how it helps to suppress appetite.
A recent study published in the journal Nature outlines how fibre may be converted directly to a salt molecule called acetate. When the gut bacteria breaks down fibre, acetate is released as a byproduct. The more fibre, the more acetate.
The study discovered that acetate goes directly to the brain to turn off the feeling of hunger. Could this be the Holy Grail of obesity?
The fibre used in this study involving mice was inulin, which is derived from the roots of plants, most often chicory. It is a popular addition to many packaged foods that are traditionally devoid of fibre.
This means that inulin doesn't have the same bulking properties of other fibres such as wheat bran, so it hasn't been considered for any cholesterol lowering or digestive motility (or regularity) properties. It is considered prebiotic as it feeds good fermentation in the bowel – still a tremendous benefit.
Its ability to suppress hunger is an interesting finding to be sure, but where does it go from there?
The fervent hope is that creating an acetate pill will help turn off the hunger message and control weight gain or promote weight loss. But even if you could control the sensation of hunger, which is a big if, there are so many more pieces to the obesity puzzle.
My main objections to this line of thinking are:
1. Simply turning off hunger may mean that all foods are forgotten, including the nourishing ones required to support health.
2. People eat to feed all kinds of hunger, not just the growling tummy one.
3. Isolating one ingredient from a whole food hasn't had a lot of luck in other arenas.
4. Human bodies may respond differently than mice.
5. It is critical that information like this isn't used to rationalize that junk food, fortified with inulin, is good for you. Adding inulin to real food may be a good idea, but nutrient-free food will always be nutrient free.
What this news should tell us is that fibre not only fills the bowel and bulks stool to remove waste effectively but that it also helps control hunger. If you're inspired to take another look at fibre in your diet, aim for 25 to 35 grams a day and start at breakfast. You really want a variety of fibre sources from fruits, vegetables, nuts and beans.
A good fibre day looks like this:
- Oats with chia seeds at breakfast.
- A handful of nuts as a snack.
- Three to four cups of salad at lunch.
- Cooked fresh vegetables and whole grains at dinner.
- If you are choosing pasta or snack foods, opt for those containing inulin over those that don’t.
Theresa Albert is a food communications consultant and a registered nutritionist based in Toronto. She blogs here and you can follow her on Twitter @theresaalbert