Pretty much every health professional will tell you to eat more fiber. Not only does the fiber from fruits and vegetables fill you up without providing many calories, it is also:
- A key part of maintaining a healthy microbiome
- Shown to reduce the severity of food allergies
- Shown to be the primary factor associated with successful aging (aging without depression, disabilities, or disease)
- Shown to help with weight loss and blood sugar control
- Shown to reduce the risks of developing cardiovascular disease
- And shown to reduce overall mortality risk and improve longevity
While fiber’s role in helping with weight loss may be a more immediate benefit, the majority of the benefits don’t really become apparent for decades. It’s one of the reasons why people still don’t listen to the advice to add more fiber into their diets. If we can’t feel the benefits from it right away (or the harms from not eating it), then does it really matter?
An improved diet improves happiness
Some interesting new research from the University of Warwick sheds light on another short-term benefit that should make you consider increasing the amount of fiber you eat. The study followed over 12,000 people to assess if increasing the amount of fruits and vegetables in their diets could improve their psychological well-being. Not surprisingly, they found that happiness increased incrementally for each additional serving of fruits or vegetables per day. They concluded that the increase in life satisfaction for people that went from virtually no fruits or vegetables to 8 servings per day was the equivalent of going from unemployment to employment. They said the effects of this change in diet occurred within a 2 year timeframe.
I’m actually surprised it took that long. I chock it up to the researchers trying not to be too enthusiastic with their findings (the study isn’t published yet, so I haven’t been able to dig into it thoroughly). As I said in the article about our 3 Day Cleanse Meal Plan, most people are surprised by how much better they feel after ditching the processed food and effectively going on a fruit and vegetable boot camp for three days. Processed foods not only make you feel physically lousy, but they can contribute to depression and other mood disorders.
What is a serving?
Eight servings probably sounds like a lot (and it is), but increasing your fiber intake by any amount will help. My typical advice still stands, consider all vegetables and many whole fruits like apples, berries, and slightly green bananas to be free calories. The benefits they provide for gastric emptying and blood sugar control will fill you up long before you can overdo it. If you want to get a visual idea of what a serving looks like, you can see some examples here for fruits and vegetables.
How does it work?
The researchers at the University of Warwick believed the happiness improvements may come from increased consumption of antioxidants known as carotenoids. Previous research has demonstrated an interesting correlation between the levels of carotenoids in the bloodstream and the person’s level of optimism, but not all fruits and vegetables contain carotenoids. What they all do have in common is fiber, and strengthening your microbiome with fiber has definitely been shown to improve mood and reduce anxiety. A large percentage of important neurotransmitters like dopamine and serotonin are actually manufactured by the bacteria in your gut. As I mentioned in the microbiome article, these trillions of organisms want to keep their home (you) happy so you can go out and get them more food. A happy host is also more likely to interact with other people which then gives them the opportunity to spread to new places. It’s a fascinating relationship but the end result is that if you keep the bacteria in your gut happy by feeding them the fiber they need, they will not only keep you healthy but happy as well.