Applying KPIs to diet: Ranking Fruits and Vegetables
Can you compare apples to oranges? Let’s try it out.
My grocery store ran out of my 3 favorite fruits last 3 weeks in a row (a Brexit consequence), which made me question my choice of fruits and wonder what are some good alternatives. I knew that fruits like grapes or bananas are very sweet whereas a fruit like avocado is very calorie-dense. Does that mean I care only about calorie density? only sweetness? Why? Why do I eat fruits at all?
Here is a metrics-driven take on dieting.
Like it did for me, I hope going through this exercise helps you understand KPIs, learn data analysis and synthesis, and use it as a cheat sheet for choosing fruits and vegetables if/when you are maintaining a diet.
What is the purpose of fruits and vegetables in a diet?
I recently hired a coach on Fittr. Although the coach didn’t give me explanations about the diet plan, follow-up questions to him and research helped piece together some of these thoughts. I relied primarily on Anita Bean’s Sports Nutrition book and HSE’s guide on diet control for GD to understand the reasoning behind the diet plan. Through that timeframe and thanks to the coach, I learned about the latest nutrition and muscle-building science but also some hard truths about the foods I ate. I’ll focus on the parts related to fruits and vegetables.
First, the basics. Fruits and vegetables are a good source of dietary fiber. They are valuable to add to one’s diet because they have soluble and insoluble fiber.
Both reduce the rate of digestion and
insoluble fiber helps in regular and smooth bowel movements.
Reducing the rate of digestion helps...
make you feel full for longer (since your feeling of hunger is not in sync with your body needing an intake of food)
low GI carbs are absorbed better into muscles.
I found a visual that is close to my understanding of this information.
The diet plan did not differentiate between insoluble and soluble, so I have learned to look at them together. As long as the rest of one’s diet is balanced, looking at total fiber should suffice. The general advice is to aim for 30g of fiber intake a day.
Next, let’s look at the diet plan I was working with. Combining the knowledge of the role of fiber and the suggested intake of it, we can try to understand the implicit KPIs governing diets recommended by experts.
Lunch: minimum 150g vegetables (pre-cooked weight)
Dinner: minimum 150g vegetables (pre-cooked weight)
Snacks: 100 - 400kcal worth of fruits. A different allowance in different weeks to prevent metabolic adaptation.
Vegetable options: Any vegetables except potatoes, sweet corn, carrot, and green peas.
Fruits: any fruit is ok. Decide on the amount based on the calorie goal and the calorie-density.
Onion: I was recommended at max 1 onion per day, where the onion gets used in the cooking.
Tomato: I was recommended to eat as many or as little tomatoes as I want.
I did not go full-on cattle-style herbivorous, just eating fruits and vegetables for my diet; these are just the relevant portions of the diet.
We wanted to deduce the implicit KPIs behind the diet plan. From the above diet plan, we can deduce:
The vegetables seem to have a lower bound, not an upper bound or a recommended value. This suggests the diet assumed low calories for the vegetables, given that it was a hypocaloric diet.
The vegetables not recommended are probably high in calories. Let’s call these vegetables the exception vegetables.
Tomatoes are either very high in water content and/or very low in fiber content to be allowed to be eaten as much or as little as interested.
The Fruits are recommended for snacks. Snacks are eaten to satisfy one’s hunger between meals. So, fruits are considered as foods with high satiety.
High Satiety foods are usually low in GI. Since Fruits have a significant amount of sugars, this suggests they have something to lower the GI despite the sugar content.
Since fruits are raw, raw plant foods have a good amount of fiber, and fiber lowers GI, fruits might be a good source of fiber for our diets.
The diet plan doesn’t help deduce that vegetables are included for their fiber and they reduce the GI of the meals. We’ve uncovered these benefits of vegetables in the Diet Basics section, so wanted to remind you about that.
I’ve learned from my earlier long articles that long articles aren’t great to consume via email. So, I’ve split this into a three-part series. In the next part of this article, we will use nutrition data of vegetables to compare and rank them. Given we had more constraints on consuming vegetables than fruits in the diet, I am more curious to explore that first. In the third article, we will compare apples to oranges and more.