Dan's Plan

Chefs love to add dietary fat to meals, and for a good reason. In the 1500s, the French physician and philosopher Jean Fernell proposed that humans could directly taste fat. We now know that Mr. Fernell was correct; in addition to taste buds for salt, sweet, bitter, sour, umami, and maybe menthol, taste buds also exist for fat which contributes to the direct sensory experience of meals. This ability to taste fat could be derived from an evolutionary advantage in the ability to absorb essential fatty acids from food.

Fat helps to lubricate the mouth and blend flavors together (i.e., it creates a desirable ‘mouth feel’). It takes different ingredients from a bite of food and makes one complete sensory experience. The chemical properties of fat also release flavors from food ingredients, creating a richer olfactory (smell) experience; and smell is a fundamental component to taste. Fat, therefore, increases the sensory stimulation from a meal and makes it taste better, smell better, and feel better in your mouth. This strong taste stimulus can lead to strong feelings of pleasure in the pleasure-measuring centers of our brain.

Pleasure generation from fatty foods can alter our eating behavior and cause an imbalance between hunger-driven eating behavior and pleasure-driven eating. We’ve all experienced this: We recognize that we’re full but we continue to eat because the food tastes great. Unfortunately, chronic pleasure-driven eating may strengthens the drive to overeat, and may simultaneously weaken the signals that say ‘you’ve had enough’.

This is not to say we should not seek to derive great pleasure from food. Indeed, pleasure from eating is one of the greatest experiences life has to offer. We just need to incorporate strategies to mitigate ever-so-easy overindulgence behaviors. With that in mind, the first few bites will generate the greatest pleasure stimulation from that meal, and overeating has immediate and long-terms negative consequences (the Dan’s Plan program materials outline our approach to keep eating pleasure high while keeping quantity in check, which facilitates a lifetime of food enjoyment at your ideal weight).

BOTTOM LINE:
Part 1: Dietary fat triggers feelings of fullness, which if listened to, can help prevent overeating.

Part 2: Dietary fat triggers pleasure which can override signals that help you feel full, and becomes problematic if you regularly overeat (it makes you want to overeat all the time!).

In Part 3, we’ll discuss if fat is healthful to include in your diet.

1) Weight loss and weight maintenance
2) Health and chronic disease

On one hand dietary fat is dense with energy (9 KCals / gram, compared to ~4 KCals / gram for both carbohydrates and proteins) so for example, a few tablespoons olive oil it can easily add a lot of calories to a meals. On the other hand, dietary fat stimulates feelings of fullness when consumed in a meal. Related to health, dietary fat consumption has been associated with the increase in a variety of diseases. On the other hand, dietary fats support important physiological functions and are necessary to consume in order to be healthy.

No wonder people are confused! Let’s address question 1, first.

Question 1: Is dietary fat good or bad relative to weight loss and weight maintenance?

For weight loss, reducing fat is an easy way to reduce calories and as the Dan’s Plan program materials stress, weight loss is largely about maintaining a consistent negative calorie balance (i.e., you take in less than you burn over time and body fat is used to make up the difference in energy requirements, and you lose fat weight).

For weight maintenance, the story may be different. Dietary fat can facilitate weight maintenance or weight gain depending on your EATING BEHAVIORS. When eaten, fat stimulates the production of episodic peptides in your gut that signal satiation (meal termination or when to stop eating) and satiety (post meal suppression of hunger).
In fact, there are several lines of evidence that suggest dietary fat is useful for weight maintenance; here are three interesting points to consider:

1. Around 1980, the food industry started to reduce the amount of fat in foods in order to attempt to address the fact that people had slowly been gaining weight over the previous 2 decades. From that point in time, after which fat had been reduced in many food products, the spike in prevalence of people categorized as either overweight or obese took a drastic turn for the worse.

2. Recently, a study from Susanne Erikson in Sweden showed that children who drink whole fat milk have significantly lower BMI’s that those children who drank milk products with lower fat contents.

3. Dr. Brian Wansink, a world leader of food behavior research, conducted a study to see how many calories people consumed in a meal where bread was provided alone or in combination with olive oil before dinner. The olive oil group consumed significantly less calories than the group provided bread alone.

These findings are by no means conclusive that eating fat helps maintain weight but are suggestive of a possible connection. The difference of whether dietary fat may promote weight gain or weight maintenance, likely has to do with your behaviors around eating. When a person is attuned to listening to their hunger / fullness signals (i.e., they stop when they’re full, limit eating out of boredom), then dietary fat helps a person to not overeat. If you know how to pay attention to your signals for satiation (when to stop eating) and satiety (don’t eat when you’re not hungry), fat is useful because it helps you sense your fullness from a meal and abates hunger in the post meal period.

Tomorrow, we’ll talk about how dietary fat can promote overeating.