Eating and drinking are essential human activities, but how exactly do our bodies process flavors and sensations from food and drink? Let’s explore the fascinating science behind taste, smell, and our experience of flavor.

What Happens in the Body When We Feel Hungry?

What is the biological mechanisms behind feeling hungry? Overall hunger stems from a “drive to eat” determined by our resting metabolic rate and physical activity levels. On a meal-to-meal basis, an empty stomach, low blood glucose, and appetite hormones trigger hunger signals to the brain’s appetite center in the hypothalamus. This motivates us to seek out food to replenish energy stores.

Hunger signals can diminish over time through fasting as the body produces ketone bodies that suppress appetite. External factors like distraction or busyness can also make us forget we’re hungry. However, this varies between people – some are very in tune with hunger cues.

Why Do We Sometimes Want to Eat When Not Hungry?

We have several “appetite systems” in the brain. The hedonic system drives us to eat for pleasure, even when physically full. For example, the temptation of a delicious dessert can override sensations of fullness after a large meal. This hedonic drive for tasty foods involves both physical and psychological factors.

Does Watching TV Affect Taste Perception?

Some studies showing that distraction activity, like watching TV, reduces attention to food. People report food is less intensely flavorful with TV on. Distraction means we don’t rely on physical fullness cues and instead eat more according to the number of “food sensations.” Mindful eating leads to faster satisfaction with less food.

Why Does Airplane Food Taste Bland?

The airplane environment suppresses perceptions of saltiness, sweetness, and flavor intensity. Low cabin air pressure, very dry air, and loud background engine noise all contribute. Food providers compensate by adding more salt and sugar.

One exception is umami flavor, which remains strong – possibly explaining why tomato juice and Bloody Mary’s are popular on planes. Serving umami-rich foods could improve flavor without added salt and sugar.

Can “Sonic Seasoning” Enhance Airline Meals?

Some airlines have experimented with “music seasoning” to enhance taste by removing engine noise. High-pitched, tinkling sounds bring out sweetness, while dissonant notes enhance sour flavor. Custom noise-cancelling headphones could further improve the dining experience. Some airline meals are designed to engage all the senses, including crunchy, textured foods and strong umami flavors.

What Happens to Food Weight During Digestion?

Contrary to popular belief, we don’t turn food into energy. Food consists of atoms that can only turn into energy by annihilating with antimatter. Instead, digestion and metabolism break food into molecules that become carbon dioxide, water, and urea. We slowly “vaporize” food by breathing out carbon atoms from carbohydrates and exhaling carbon dioxide from other nutrients. Over hours, metabolism turns 100 grams of food into about 75 grams of exhaled carbon dioxide plus 25 grams of water. On a parked airplane, this weight loss is miniscule and insignificant.

How Does Taste Change for Astronauts in Space?

Flavor and palatability help ensure astronauts eat enough for nutrition. Spence notes that space anorexia is a real concern, possibly explained by reduced smell capacity from fluid shifts in zero gravity. Carefully calibrated but unappetizing astronaut food highlights the importance of taste, smell, appearance and naming in promoting flavor.

Do Other Animals Season Their Food?

Some species use tools to prepare food, like chimps fishing for termites or birds hanging toxic grasshoppers to “age” them. But Japanese macaques go further by washing sweet potatoes in the ocean, seemingly for the salty and improved flavor. This cultural trait spread through monkey groups over generations. It provides a uniquely non-human example of seasoning food for taste beyond nutritional needs.

In Conclusion flavor perception

The myriad factors influencing flavor perception highlight the complex interplay of biology, psychology, physics, and culture in our experience of food. Some fascinating insights from the frontiers of flavor science, like monkey potato washers to airline meal design. Understanding the science behind taste and smell not only sheds light on human physiology, but can lead to healthier and more satisfying eating experiences.

Exercise Provides Added Benefits for Insulin Resistance Beyond Just Weight Loss

Insulin resistance is a growing health concern, as rates of obesity and type 2 diabetes continue to rise globally. While weight loss through diet is known to help improve insulin sensitivity, a new study sheds light on the added benefits of exercise beyond just the scale.

Study Design: obese, prediabetic volunteers

The study recruited obese, prediabetic volunteers and put them on a 25% caloric deficit diet for 5 months, providing all their food to ensure compliance. This led to an average 10% weight loss. The diet was relatively high in carbs (70% of calories) from whole, complex sources like fruits, vegetables and whole grains. The remaining 30% of calories were split between fat and protein.

The participants were divided into two groups:

• Diet only
• Diet plus exercise 6 days per week (4 days cardio, 1 day weights, 1 day HIIT)

The aim was to compare the effects of the two interventions on insulin resistance and other metabolic factors.

Results on Body Composition and Metabolic Markers

Both groups lost around 10% of initial body weight, with similar reductions in BMI and body fat percentage. This makes sense given they ate the same hypocaloric diet.

Fasting glucose, insulin, triglycerides, and A1c also improved in both groups, as expected with caloric restriction and weight loss. No significant difference was seen between diet alone and diet plus exercise for these markers.

Diet Plus Exercise Had Greater Improvements in Insulin Sensitivity

Here’s where things get interesting. While the diet alone group increased insulin sensitivity by 48%, the diet plus exercise group improved by 110% – more than double!

Looking specifically at liver insulin sensitivity, the diet alone group increased by 88% versus 160% for diet plus exercise.

Clearly, adding exercise provided significant benefits beyond just the dietary calorie deficit and weight loss.

Potential Mechanisms

What mechanisms could be behind this added benefit of exercise? It doesn’t appear to be changes in body composition. There was no significant difference in fat free mass or lean mass between groups, possibly because strength training was only performed once weekly.

However, the researchers did find differences in gene expression in muscle tissue. Certain genes related to mitochondrial function and blood vessel growth were more active with exercise. While interesting, they did not conclusively show these gene changes actually caused the metabolic improvements.

The exact molecular pathways still need further research. But we can say exercise provides benefits to insulin sensitivity over and above weight loss alone.