Food Reward: a Dominant Factor in Obesity, Part I

A Curious Finding

It all started with one little sentence buried in a paper about obese rats. I was reading about how rats become obese when they're given chocolate Ensure, the "meal replacement drink", when I came across this:

...neither [obesity-prone] nor [obesity-resistant] rats will overeat on either vanilla- or strawberry-flavored Ensure.

The only meaningful difference between chocolate, vanilla and strawberry Ensure is the flavor, yet rats eating the chocolate variety overate, rapidly gained fat and became metabolically ill, while rats eating the other flavors didn't (1). Furthermore, the study suggested that the food's flavor determined, in part, what amount of fatness the rats' bodies "defended."

As I explained in previous posts, the human (and rodent) brain regulates the amount of fat the body carries, in a manner similar to how the brain regulates blood pressure, body temperature, blood oxygenation and blood pH (2). That fact, in addition to several other lines of evidence, suggests that obesity probably results from a change in this regulatory system. I refer to the amount of body fat that the brain defends as the "body fat setpoint", however it's clear that the setpoint is dependent on diet and lifestyle factors. The implication of this paper that I could not escape is that a food's flavor influences body fatness and probably the body fat setpoint.

An Introduction to Food Reward

The brain contains a sophisticated system that assigns a value judgment to everything we experience, integrating a vast amount of information into a one-dimensional rating system that labels things from awesome to terrible. This is the system that decides whether we should seek out a particular experience, or avoid it. For example, if you burn yourself each time you touch the burner on your stove, your brain will label that action as bad and it will discourage you from touching it again. On the other hand, if you feel good every time you're cold and put on a sweater, your brain will encourage that behavior. In the psychology literature, this phenomenon is called "reward," and it's critical to survival.

The brain assigns reward to, and seeks out, experiences that it perceives as positive, and discourages behaviors that it views as threatening. Drugs of abuse plug directly into reward pathways, bypassing the external routes that would typically trigger reward. Although this system has been studied most in the context of drug addiction, it evolved to deal with natural environmental stimuli, not drugs.

As food is one of the most important elements of survival, the brain's reward system is highly attuned to food's rewarding properties. The brain uses input from smell, taste, touch, social cues, and numerous signals from the digestive tract* to assign a reward value to foods. Experiments in rats and humans have outlined some of the qualities of food that are inherently rewarding:

• Fat
• Starch
• Sugar
• Salt
• Meatiness (glutamate)
• The absence of bitterness
  
• Certain textures (e.g., soft or liquid calories, crunchy foods)
• Certain aromas (e.g., esters found in many fruits)
• Calorie density ("heavy" food)
  

We are generally born liking the qualities listed above, and aromas and flavors that are associated with these qualities become rewarding over time. For example, beer tastes terrible the first time you drink it because it's bitter, but after you drink it a few times and your brain catches wind that there are calories and a drug in there, it often begins tasting good. The same applies to many vegetables. Children are generally not fond of vegetables, but if you serve them spinach smothered in butter enough times, they'll learn to like it by the time they're adults.

The human brain evolved to deal with a certain range of rewarding experiences. It didn't evolve to constructively manage strong drugs of abuse such as heroin and crack cocaine, which overstimulate reward pathways, leading to the pathological drug seeking behaviors that characterize addiction. These drugs are "superstimuli" that exceed our reward system's normal operating parameters. Over the next few posts, I'll try to convince you that in a similar manner, industrially processed food, which has been professionally crafted to maximize its rewarding properties, is a superstimulus that exceeds the brain's normal operating parameters, leading to an increase in body fatness and other negative consequences.


* Nerves measure stomach distension. A number of of gut-derived paracrine and endocrine signals, including CCK, PYY, ghrelin, GLP-1 and many others potentially participate in food reward sensing, some by acting directly on the brain via the circulation, and others by signaling indirectly via the vagus nerve. More on this later.

Grilled Tuna Steaks

(makes 4 servings)

Ingredients:

• 4 tuna steaks (4 oz. each)
  
  


• 2 tbsp reduced sodium soy sauce
  
  


• 1 tbsp Worcestershire sauce
  
  


• 1 tsp sugar
  
  


• 1 tsp whole-grain mustard
  
  


• 1 tbsp vegetable oil
  
  


• parsley for garnish, chopped (optional)
  
  


• lemon wedges (optional)
  
  

Preparation:

• Place tuna in a shallow dish in a single layer.
  
  


• Whisk together the soy sauce, Worcestershire sauce, sugar, mustard, and vegetable oil in a small-sized bowl until combined.
  
  


• Pour marinde over tuna and gently turn steaks until well-coated on each side. Cover with plastic wrap and refrigerate for at least 30 minutes up to 2 hours.
  
  


• Prepare grill.
  
  


• Remove tuna and reserve marinade for basting. Grill tuna for about 10 to 15 minutes, turning once and basting often with reserved marinade.
  
  


• Serve steaks with lemon wedges and garnished with parsley.
  
  

Make 4 Servings:

Weight loss recipes Amount Per Serving(¼ of recipe (131 g)): 162 Calories, 27 g Protein, 2 g carbohydrates, 0 g Dietary Fiber, 5 g fat, 1 g saturated fat, 51 mg cholesterol, 417 mg sodium

Life is precious

I have a friend whose diet was impeccable and taught yoga.  She was as beautiful on the inside as she was on the outside, always fashionable with a bright smile.  Her lifestyle was the epitome of health and someone I looked up to as an example.  You can imagine my surprise when she unexpectedly passed away this week at  age 49 from cancer.  She was by far, the healthiest woman I know and now she's gone.

A question that crossed my mind was, "Why put forth all the efforts to be healthy if you could die early anyway?"   I mean, if you are going to get a life threatening illness young, why spend all that time checking labels, chopping produce and searching for tasty and healthy recipes so you can live longer? I felt a little guilty when I entertained that thought for a few moments longer than I should, but after talking to others, I found that it was a pretty common thought.

So what is the answer? It's simple. If I was currently diagnosed with a life threatening illness, I would beat myself up. "Why didn't I eat better? Why didn't I workout harder? Why didn't I just DO better? I do pretty good, but I admit I could do a whole lot better! As for my friend, I really doubt if she berated herself with such questions. What peace that would be, knowing I did everything on my end, in the face of such heart breaking news.

I know everything in life happens for a reason, I honestly do.  I also know that there are consequences for every action taken.  More often than not, our lifestyles determine the quality of life we live and if we do our best in our health efforts, we will be rewarded.  Even with heart breaking news, if a life is lived to the best of our ability, we can still have peace.

Grilled Pork Chops with Grape and Fig Chutney

(makes 4 servings)

Ingredients:

• ½ cup onion, chopped
  
  


• ½ cup dried figs, chopped
  
  


• ½ cup red wine vinegar
  
  


• ¼ cup dry red wine
  
  


• 1 tbsp sugar
  
  


• 2 tsp paprika
  
  


• 1 tsp peeled and grated fresh ginger
  
  


• 1 3 inches cinnamon stick
  
  


• 1½ cups seedless red grapes, halved
  
  


• 4 medium sized pork chops
  
  


• 2 tsp olive oil
  
  


• Salt and pepper, to taste
  
  

Preparation:

• Prepare grill.
  
  


• Combine onion, dried figs, red wine vinegar, dry red wine, sugar, paprika, ginger and cinnamon stick in a medium saucepan and heat to medium-high heat. Bring to a boil and cook, uncovered for about 8 to 10 minutes. Stir in grapes and reduce heat and simmer for about 20 minutes then remove and discard cinnamon stick.
  
  


• Brush pork chops with olive oil then sprinkle with salt and pepper. Grill on both sides until done.
  
  


• Serve chops with grape and fig chutney.
  
  

Make 4 Servings:

Weight loss recipes Amount Per Serving(¼ of recipe (253 g)): 297 Calories, 23 g Protein, 34 g carbohydrates, 4 g Dietary Fiber, 8 g fat, 2 g saturated fat, 62 mg cholesterol, 71 mg sodium

I do NOT like this book

The book
I'm on chapter two of A Course in Weight Loss, 21 Spiritual lessons for surrendering your weight forever, by Marianne Williamson. I wonder, exactly what does "surrendering your weight forever" mean?

I've decided this book is a bunch of crap. Lesson two is even more stupid than lesson one. It's titled Thin You, Meet Not-Thin You. I got about four pages into this lesson and realized I don't like this author.

Marianne talks about Divine Mind, and "One in Whose hands it will dissolve forever". Seriously? Sounds kind of Harry Potter-ish to me. If she's talking about God then why doesn't she just say "God"?

When I read "Fat cells will dissolve permanently when they are dissolved through the power of love." I almost couldn't stop laughing. That's news to me. I thought those little guys were with me for life. I knew they could shrink, but I didn't know a little love could get rid of them.

I'm sure she was speaking figuratively and not literally, but so much of her writing is like a puzzle. It sounds nice but it doesn't make any sense.

Lesson one, tearing down the wall, which involved looking at the darkness in my life, was a terrible exercise. Dredging up old grievances and sadness in my life did nothing for my soul. Examining them in detail was horribly depressing.

This is by far the worst weight loss book I've ever read in my life, and I've read a lot of them.

After reading this book for a few days, I remembered buying another Marianne Williamson book several years ago. I had totally forgotten about that book. I can't remember the name of it. That was when I respected Oprah and she was promoting it at the time. I hated that book. In fact, that's when I was very involved with my church, reading the Bible daily, and of course, daily prayer. I found Marianne's writing offensive, and I still do.

I think there might be some value in this book. Sadly, so much of it is New Age garbage that you have to try to weed through to get to anything worthwhile, I really don't think it has much overall value.

I did a little research on Marianne last night and found an interview she did several years ago. Personally, I think she's a little crazy. Sure, we're all a little bit crazy, but most of us aren't out there selling our brand of crazy to the masses.

Buyer beware

And life goes on
It's only Tuesday but yesterday was long! After a couple of sleepless nights over the weekend (thanks to that damn book), I awoke exhausted on Monday morning. I felt like I hadn't slept all weekend. I managed to drag myself to the gym, but my heart wasn't in it.

Saturday I had done a new upper body workout that killed my triceps, biceps and deltoids. My arms are still very sore. After purchasing a great new magazine that I totally love, "Muscle and Fitness hers", I read about doing supersets or compound sets. I remember doing these years ago, but had forgot all about them.

You pick two or three exercises for one body part and then you complete one set of one exercise and go immediately into the next one, alternating until you complete all sets. Compound sets are a great way to get better results in less time, stimulating muscle growth while also bumping up fat loss. I also found it a lot less boring.

After the gym I only had a half day of work because I had a dentist appointment. I go three times a year for a cleaning, but this wasn't a normal visit. It was to "look at my crown". I had a crown put on a molar three years when my dentist saw a "shadow" in the x-ray. I had no pain in that tooth but he convinced me I needed a crown, which resulted in three years of cold sensitivity and often pain.

The "looking at my crown" turned into a two-hour root canal. My dentist is a "pain-free" dentist and I didn't feel any pain, other than sitting there for two hours while he drilled, prodded, poked, drilled some more, more poking and prodding and more drilling. I had my iPod cranked up but I had no idea it was going to be two freaking hours in that chair.

I was on nitrous oxide the entire time so I was in happy land.When I came home I took a Valium he had prescribed because as soon as the numbness wore off I wasn't in happy land anymore. After dinner, a bowl of delicious homemade beef vegetable soup I made in the pressure cooker (my new best friend), I became violently ill. Like I thought I was going to die ill. I couldn't stop throwing up. It was horrible.

I'm not sure what made me so sick. This is the first beef I've eaten in over two years. It was fresh, as well as all the vegetables. Maybe it was a reaction to the Valium, but I've never had that happen before.

At least I'm over it now and I've tested out the crown. I can drink ice water and let it hit that tooth without screeching in pain. I guess it was worth it.

Now, off to the gym. I have some new glute exercises to try (from the magazine - love it!).

One last thing, as my friend Roxie often says....be kind to yourself today (and others). :)

Garlic and Corn Risotto

(makes 4 servings)

Ingredients:

• 3¾ cups fat-free chicken broth
  
  


• 4 cloves garlic, chopped
  
  


• 1 cup uncooked Arborio or long grain rice
  
  


• 2 cups frozen whole kernel corn
  
  


• ¼ cup low-fat Mozzarella cheese
  
  


• ⅓ cup low-fat Parmesan cheese
  
  


• ¼ cup fresh parsley or cilantro, chopped
  
  

Preparation:

• In a large saucepan, bring ⅓ cups of the broth to boil. Add garlic, cook for about 1 minute, stirring occasionally.
  
  


• Stir in rice and corn then cook for about 1 minute.
  
  


• Add remaining broth and bring to a boil then reduce heat to medium-heat. Cook uncovered until rice is tender and creamy (about 15 to 20 minutes), stirring often to absorb liquid.
  
  


• Remove from heat then add Parmesan cheese, Mozzarella cheese and parsley.
  
  

Make 4 Servings:

Weight loss recipes Amount Per Serving(¼ of recipe (372 g)): 339 Calories, 16 g Protein, 56 g carbohydrates, 3 g Dietary Fiber, 6 g fat, 3 g saturated fat, 10 mg cholesterol, 10 mg sodium

Grilled Tofu and Mushroom Brochettes

(makes 4 servings)

Ingredients:

• 12 oz. white button mushrooms
  
  


• 10 (½oz.) package of firm beancurd (tofu)
  
  


• 4 tbsp white wine vinegar
  
  


• 3 tbsp olive oil
  
  


• 1 lemon
  
  


• 1 garlic clove, crushed
  
  


• 1 tbsp fresh rosemary, chopped
  
  


• 1 tbsp cilantro, chopped
  
  


• 1 tbsp fresh basil, chopped
  
  


• Salt and pepper, to taste
  
  

Preparation:

• Wash outside of lemon thoroughly with warm water and soap. Pat dry then grate peel and set aside. In a medium bowl, slice lemon in half and squeeze out juice.
  
  


• Add the garlic, olive oil, white wine vinegar and chopped herbs with the lemon juice and mix well. Add salt and pepper to taste.
  
  


• Using a damp cloth, clean mushrooms and remove any excess soil. Slice mushrooms in half and set aside.
  
  


• Using a sharp knife, slice the tofu into medium chunks. Thread tofu alternated with sliced mushrooms onto metal or wood skewers. Place brochettes into a shallow pan and pour the lemon-herb marinade over the skewers, coating evenly. Cover with plastic wrap and refrigerate for about 1-2 hours.
  
  


• Prepare grill.
  
  


• Remove brochettes and set aside marinade for basting. Cook brochettes over a hot grill, brushing often with the reserved marinade until cooked through (about 6 minutes).
  
  


• Serve with an extra sprinkling of chopped fresh herbs and lemon wedges.
  
  

Make 4 Servings:

Weight loss recipes Amount Per Serving(¼ of recipe (200 g)): 164 Calories, 8 g Protein, 8 g carbohydrates, 2 g Dietary Fiber, 12 g fat, 2 g saturated fat, 0 mg cholesterol, 31 mg sodium