Let’s love fibre- Chapter 3: Fibre and weight management
Welcome to the final part of the fibre series! Today we will discuss the potential effects of fibre on weight and appetite, based on possible biological mechanisms and results from human studies.
Eating fibre could help with feeling full for longer
– Fibrous foods also need more chewing and prolonged mastication also increases satiety signals .
– Propionate is one of the short-chained fatty acids that comes from soluble fibre fermentation in the gut. Proprionate may stimulate the production of PYY and GLP-1 (GLP-1 is another satiety-inducing peptide) from the enterocrine L cells in the small intestine .
– On Chapter 1 it was mentioned that soluble fibre delays the digestion and absorption of other nutrients of a meal because it forms a gel that “traps” other nutrients. This property could contribute to feeling full for longer because:
- Gastric emptying is delayed. This means that food stays in your stomach for more time and you may feel hungry later than usual .
- Soluble fibre molecules can retain water. As a result the food volume in the stomach is increased, which results to gastric distension. Gastric distension is involved in signals of the nervous system that promote satiety .
- Meal nutrients, including fat and protein, stay in the small intestine for longer. Fat and protein stimulate the production of peptides (like cholecystokinin and PYY) that interact with the nervous system and promote satiety .
Fibre can reduce a meal’s energy density.
A meal’s energy density is the amount of energy (in kcal or kJ) per portion. Fuit and non- starchy vegetables are great sources of both soluble and insoluble fibre. They are overall low calorie foods too. A a result, the same type of meal can contain less energy per portion when we add fruit/vegetables to it. Thus, we can eat the same volume of food and consume less calories, while feeling full for longer. Let’s see a few examples of how we can do that:
- Add carrots, bell peppers and tomatoes to legume recipes instead of eating a full portion of just legumes (The carrot and lentil stew recipe is a good example to check!)
- Add vegetables to pasta sauces or cook your pasta with vegetables.
- Instead of eating only potatoes with your fish/meat, you could replace part of your potatoes with other non- starchy vegetables.
- Instead of eating a bowl with just cereal or oats, you could replace part of your cereal with fruit.
Human weight loss studies have shown that reducing energy density by increasing fruit and vegetables could contribute to losing weight and keeping the weight off for longer . The POUNDS study results showed that those who consumed more fibre and less energy dense meals lost significantly more weight. It was also easier for them to stick to their nutrition program, no matter what their diet was (4 different types of diet were followed) .
Please keep in mind:
- Even if fruit and vegetables are overall low energy foods, cooking methods are very important! For example, frying vegetables and caramelizing fruit can increase their energy value a lot. If you are trying to lose or maintain your weight, this is a very common mistake that could impede your progress.
- Starchy vegetables (eg potatoes, corn), legumes, cereal and pasta are sources of fibre but can be quite energy dense. Always pay attention to your portion size. You could try eating these foods combined with non- starchy vegetables/fruit.
Overall, fibre is a very important component of a healthy lifestyle and research is still ongoing! As always, if you have any particular health issues it is always wise to consult with a registered healthcare professional before making any dietary changes.
Thank you for reading!!
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