
#49: What you eat effects how much you eat
Live Long and Well with Dr. Bobby
Intro
Dr. Bobby DuBois opens the episode, poses the central question about how food choice affects intake, and welcomes listeners to episode 49.
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Can the type of food you eat influence how much you eat? In this episode, I explore how calorie density, texture, protein content, hydration, and even your perception of food can all affect fullness—and how understanding these levers can help you better manage your weight without feeling deprived.
We start by revisiting the foundational idea that maintaining a healthy weight impacts your risk of heart disease, diabetes, and cancer. While previous episodes discussed eating slowly and using smaller plates, today’s focus is on how the specific foods you choose can directly affect how much you consume.
Drawing from both personal anecdotes—like my wife Gail’s success with a no-flour, no-sugar approach—and recent science, I explore five key factors. First, calorie density plays a powerful role. In a randomized crossover trial, participants ate 813 more calories per day when consuming ultra-processed foods, even though meals had identical calories and macronutrients. Foods engineered to be hyper-palatable often pack in calories without promoting fullness.
Next, we dive into satiety—that subjective feeling of fullness. A Satiety Index study found that boiled potatoes, oatmeal, apples, and beef left participants feeling fuller than white bread or croissants. Why? One reason might be energy density, as demonstrated in another trial where high-fat lunches led participants to eat nearly 500 extra calories.
We also explore food texture. In a study comparing soft vs. hard meals, participants consumed 20% more from softer options. A similar principle applies to fruit vs. fruit juice, where a five-week trial showed that eating a whole apple before a meal reduced calorie intake by 187 calories compared to juice.
Protein also emerges as a standout. In a small study, a protein-based snack delayed hunger by 60 minutes—far more than fat or carbs. And then there’s hydration. Drinking water before meals may curb appetite, supported by a randomized trial and a systematic review showing that two cups of water before each meal led to significant weight loss over 3–12 months.
Finally, we can’t ignore the psychological piece. In the “sham milkshake” study, participants felt fuller—and had altered hunger hormone levels—based solely on what they thought they were consuming. Mind over matter, indeed.
Throughout the episode, I encourage listeners to explore these ideas with an N of 1 trial, as detailed in Episode 27
Try a protein-rich snack before dinner or a glass of water before meals and see how it changes your appetite.