Full Yet Hungry? Appetite Neurochemistry – Part I

Science-Report_Full yet hungry_Appetite neurochemistry – Part I_The-Health-Sciences-Academy

by Alejandra "Alex" Ruani — Get free science updates here.

People tell you “when you feel full, stop eating”. But what does feeling full mean anyway?

And why do we keep eating despite having a filled up, stretched stomach?

It appears that the science of feeling full is not as straightforward…

In this report, we start unravelling some of its mysteries:

Grab “Full Yet Hungry? Appetite Neurochemistry – Part I” below:

 

Download PDF NOW!

 

Conveniently download this 26-page science report. Contains links to extra reading materials and scientific references.

Topics covered in this report:

  1. Full yet hungry?
  2. There is “full” and “full”
  3. Fat, leptin and hunger
  4. More than a “satiety hormone”
  5. Graph: Your leptin levels
  6. The body as a machine
  7. The psychology of eating
  8. Hunger and reward
  9. Can leptin lower food reward?
  10. Dopamine and reward
  11. Stimulating one type of neurons
  12. Genetics, laser and neurons
  13. How to ask a mouse
  14. The brain likes dopamine
  15. Sugar is rewarding when hungry
  16. Leptin decreases sugar reward
  17. Leptin and obesity
  18. Your key takeaways
  19. Learn more
  20. References and resources

 

Download PDF NOW!

 

Download the entire Appetite Neurochemistry series by clicking on the links below:

 

VOTE IN OUR NEW POLL:

FULL BUT STILL HUNGRY?

How often do you keep eating despite having a filled up, stretched stomach?
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Alex Ruani leads the research division at The Health Sciences Academy, where she and her team make sense of complex scientific literature and translate it into easy-to-understand practical concepts for students. She is a Harvard-trained scientific researcher who specialises in cravings and appetite neurobiology, nutrition biochemistry, and nutrigenomics. Besides investigating and teaching the latest advances in health and nutrition science, Alex makes it easier to be smarter with her free Science Catch-ups every other Thursday.
Connect with Alex via email.


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39 Comments

  • jamie

    Reply Reply May 14, 2015

    I don’t overeat alot, however there are a few foods i fall foul from.
    Mainly takeaways, chinese food, curry, kebabs, pizza and my favourite food spaghetti bolognese.
    For the takeaways it’s probably a mental thought that i have paid alot of money for the food and to not waste.
    The bolognese is simple because i love this food.

    • caroline

      Reply Reply August 29, 2016

      Ive tried to stop take out! but ive found that Sainsbury have a nice range of curries on their deli counter. I’m a vegetarian so my options are limited. But their veggie curry and samosa is to die for, so once a month i treat myself.

      Also i make my own deserts from natural food combination, my fav go to for a sweet tooth is….coconut date balls. Simple to make yourself.

  • philip smith

    Reply Reply May 14, 2015

    Even though much of what is in the report I am already aware of I love the report. It presents the main points in a succinct and easy to read format which gives a brief summary of the main points.

    • Alex

      Reply Reply May 15, 2015

      Philip – glad you enjoyed it, we love to explain experiments, makes learning more fun :-)

  • Alejandro Salcedo

    Reply Reply May 14, 2015

    HI,

    When I feel full, I keep eating because I enjoy the flavors and textures of the meal. Not because I feel hungry. I noticed that when I eat very very spicy hot food I feel hungry for long time. I suspect that some chemical in the chili may inhibits the leptin or something. I tried an experiment I saw in TV, I blindfolded myself and I kept eating until really full. To my surprise my plate was half full. I did it again two more days and was the same. I learn that we eat with the eyes first and ignore the signs of the stomach. Big eyes little stomach. Also we could get confuse by brain signals such as thirsty but we can interpret it as hunger. Eating 5 small meals a day I don’t let my stomach to stretch and feel better.

    • Chinmay

      Reply Reply May 14, 2015

      Hi Alejandro,

      This is brilliant. Thanks for sharing, I must try the experiment myself.

    • Amanda

      Reply Reply May 14, 2015

      My dad once told me something that always stuck with me – we eat junk food for the taste. It was a great encouragement for me since I started to try losing weight, because then I realized that eating more junk food would only prolongue the time that I felt its taste directly. With that in mind, it becomes a lot easier to take just one bite, one small portion and try and enjoy it as much as possible instead of practically swallowing it like I used to!
      I know what you mean, though. Eating when I’m not hungry is still something I struggle with a lot. But, as you said, we can confuse it for thirst sometimes, so drinking the appropriate amount of water always helps me with my “hunger”!

      • Philip Watling

        Reply Reply May 19, 2015

        I you drink water before eating you will eat less because the stomach will feel stretched and full faster. Never eat on an empty stomach lol

    • HealthyHappySenior

      Reply Reply May 16, 2015

      Thank you for such a wonderful and insightful comment! Tomorrow, with my meals, I am going to do the same.

    • caroline

      Reply Reply August 29, 2016

      Ive noticed lately that when im really hungry i will eat with gusto. After i eat half i sit back for a few seconds. then go back to my plate, if im eating in a more picky manner then i know im full. it works for me. Try turning all gadgets off as well, and don’t have a drink at the table and don’t drink water with a meal. either drink it an hour before or an hour later.

  • Audrey Bamber

    Reply Reply May 14, 2015

    Initially I used do eat everything on my plate, because I was brought up during wartime and it was considered unpatriotic to leave anything. But gradually I realised that being too full spoilt the enjoyment of the meal and now, most of the time, if I’m given too much I leave it and apologise to my hosts, or I don’t take too much to begin with.

  • Toni

    Reply Reply May 14, 2015

    This was so interesting, I set my students a task to research information by Robert Lustig regarding the effects of sugar and what part ghrelin plays in obesity- your report backs up much of what he says. Great timing, I will be suggesting the students subscribe to your website too. Thank you!

    • Alex

      Reply Reply May 15, 2015

      Tony – fantastic task, a huge welcome to you and your students :-)

  • Sonya

    Reply Reply May 14, 2015

    I identify with Jamie in that it is usually take aways that I find I over eat, as I don’t wish to waste the money spent. However, I find in general serving family meals in pots i.e. rice, vegetables, curries, stews etc.. and putting on the table for people to help themselves means I and the family take less and tend to over eat less.

    • Alex

      Reply Reply May 15, 2015

      Sonya – that’s a great tip, planning in advance helps!

    • caroline

      Reply Reply August 29, 2016

      I find dishing up on a smaller plate also helps. if after that serving your hungry then by all means the rest is in the kitchen.

  • JoJo

    Reply Reply May 14, 2015

    Another fascinating report, I can’t wait for part two! It was so interesting to learn about the conflict which goes on inside the body between leptin and dopamine, so much more than physical fullness is influencing what we eat!

  • DanC

    Reply Reply May 14, 2015

    I grew up living on the streets & therefore as a young man I learned to survive & strangely enough, to thrive on several small morsels of food a day. Sometimes I would often go days without food, and although this was occasionally uncomfortable, I never got to the stage where it was painful. I was lean and due to being very active in trying to stay alive and survive, I was also quite fit.

    Enter 22yrs of age & I marry my beautiful wife who is a country girl raised in a large family of boys. Well being the only daughter she was taught to cook large meals for when the men came back from the field. It started whilst we were courting, I would go to her place for a meal with her family & be full before I had got through a fifth of what she had dished me up. So every five minutes I would excuse myself & go outside & jump up & down so I could fit more in… she was a great cook & I really loved her.

    When we were married I weighed in at 165lb/75kg, by the time I was 40 I was pushing 247lb/112kg. I realised that my love for my wife had blinded me to the fact that I had trained my brain to overeat. She was in the same boat due to the family rule that “you have to finish everything on your plate”. She was feeling miserable because of being overweight and feeling run down all the time, and I was right there with her.

    When I turned 41 (about 7mths ago), I said “this madness has to stop!” So after a lot of research I put us both on a paleo diet and taught her how to eat smaller portions and then wait 10mins before she decided if she felt like she needed to eat more.

    Well I’m proud to say that without any exercise program at all, I have dropped over 50lb/23kg in 6mths, and my wife has dropped 17lb/8kg in 5mths… yes “without” exercise. We are both now fully aware of the need to “wait” for the stomach to signal that it’s full. My wife who had never really experienced this before is completely blown away by the fact that she can now eat much less, feel full & have more energy to boot. She has also commented on how she no longer has the urge to grab a candy bar when she’s out shopping because her blood sugar levels are more stable.

    Congratulations you’ve made it to the end. Thanks for hanging in there. ☺

    • Alex

      Reply Reply May 15, 2015

      DanC – thanks so much for sharing your story, I can see the both of you are getting ready for that 20th anniversary :-)

      • DanC

        Reply Reply May 18, 2015

        Yes Alex we certainly are! Not that the romance has dimmed at all over the last 19yrs, it’s just that recovery time takes a little longer. ☺

        • Philip Watling

          Reply Reply May 20, 2015

          I hear you about the recovery time, DanC, though mine is mainly due to a workout in the gym!

  • Chinmay

    Reply Reply May 14, 2015

    Thanks for sharing this post. Such a wonderful read, everytime I read your posts I feel I understand more about myself and my body. Here is an interesting research article about Leptin http://onlinelibrary.wiley.com/doi/10.1111/j.1467-789X.2010.00840.x/full

  • Sophie Ash (Research Analyst)

    Reply Reply May 14, 2015

    I really enjoyed this report; anything involving satiety and adipokines is always an interesting read! Although I was already aware of the roles of leptin and ghrelin on appetite, I had never before taken the time to understand how this relates to reward sensations. Yet another factor to consider in relation to combating obesity!

  • Gena McBrain

    Reply Reply May 14, 2015

    I continue to eat once I feel full for several reasons. One is because I’m not “satisfied”. Sometimes I’m never satisfied no matter how full I am. Another reason is because the food is good and I want to continue “enjoying” the taste. Another reason would be because it’s calming or comforting. Either way, I usually just have no will power.

  • Goulven

    Reply Reply May 14, 2015

    Alejandro, I know what you mean – the only times chilli peppers don’t make me want more is when I eat them without anything else and burn my mouth like a firs-timer… Otherwise, it makes food more exciting, doesn’t it and I tend to forget about how full I am.
    Thanks everyone for your encouraging comments!

  • Philip Watling

    Reply Reply May 15, 2015

    As I child I was always told to ‘finish the plate’ and now I think of all the starving millions in Africa and cannot throw food away. Of course this only applies for when I am not eating at home. Also remember that in a restaurant the food is damn good and I have paid for it – I will eat it all… Unless they give doggy-bags! When at home I put what I cannot finish in the fridge to eat the next day. That also saves money and in the austere times…

    Oh, btw, well done DanC in losing the weight. I haven’t dared weigh myself recently, but have lost about 2 inches round my waist. Most trousers and many belts are now too big for me, and the belly fat I gained in hospital twenty years agho has pretty much gone – see my website. That alternate day fasting diet really works :)

    • Alex

      Reply Reply May 15, 2015

      Philip – seeing how loose your clothes get (or even using a tape measurement) can be as, if not more, motivating than the scales!

      • Philip Watling

        Reply Reply May 19, 2015

        I didn’t set out to lose weight though, Alex; it just kinda happened. I certainly did not regimentaly follow the 5/2 plan. Most days I ate well and some days I stuffed my face. Once or twice a month I just went without much food – no time, forgot to cook etc. Suddenly, the weight has gone. What is more I feel great :)

    • DanC

      Reply Reply May 18, 2015

      Thanks Phillip! BTW mate 2″ is nothing to sneeze at… quite an achievement of your own. I hear you about the belts & trousers mate, I’m not a big fan of shopping but the wife and I have decided when we hit our goal weight that we are shouting ourselves a new wardrobe ☺

      • Philip Watling

        Reply Reply May 20, 2015

        I’m not complaining, DanC.

  • alessandra danesi

    Reply Reply May 15, 2015

    It was a very interesting report to read! I am very interested in everything that relates to the topic and it was extremely fascinating to actually learn whats going on in our bodies when we have that hunger feeling.
    Thinking about it, it would be much easier to actually categorise where that feeling is coming from i.e. from real hunger or not but we are all too much involved in our busy lives and globalised world to stop and reflect on it.
    This report was definitely useful to understand more our body and the millions different ways it works and I am looking forward to learn even more!

    • Alex

      Reply Reply May 15, 2015

      Alessandra – thanks so much for your lovely feedback! A million ways indeed… brace yourself for Part II :-)

  • kristene

    Reply Reply May 18, 2015

    Interesting read. How often do we keep eating even when we are full or say to myself ‘I ate to much’. When I think back to a few months ago before I was diagnosed with Diabetes, I often would eat for boredom and the when I ate sweet food, I couldn’t get the taste I was after, so would keep eating it, going through whole chocolate bars, packets of biscuits etc before my sweet craving was satisfied.

    After losing some weight and cutting out all junk food, I have found reading my hunger a lot easier. I went onto read the article about sugar. which is fascinating!

  • Tracy

    Reply Reply May 18, 2015

    I wanted to cut down portion sizes for my family because I felt that we were probably eating more than we needed to. I got rid of my dinner plates and replaced them with smaller ones. It really worked! I think that we were all in the habit of filling our plates and then eating everything on the plate. When we switched to smaller plates, we still filled them and ate everything, but the amounts were smaller. I thought some family members might just go for seconds, but that really hasn’t happened!

    • Philip Watling

      Reply Reply May 19, 2015

      That’s a great plan, Tracy. It’s the same with glasses: a standard large glass of wine will happily take 1/3 of a bottle of wine!

  • Rosana

    Reply Reply May 18, 2015

    Great information but does this also apply when it is that time of the month when nothing seems to make sense at all even knowing that it is just bingeing for a couple of days!

    • Philip Watling

      Reply Reply May 20, 2015

      I know what you mean, Rosana; every full moon I turn distinctly carnivorous :)

  • Marie Tolman

    Reply Reply May 21, 2015

    I am so enjoying the nutritional therapist course, to weave it into my wellness and resilience coaching, along with learning deeper insights into nutrition.

    As a person who has suffered eating disorders in my youth and battled with weight, not helped by health conditions, yet now not totally out of my control.

    I can’t wait to read part two, I found the report insightful, practical and digestible. Looking forward to applying to myself and clients in future, thanks again team of the Health Sciences Academy, for making sense of a subject I have always been frightened to approach.
    I think especially my age group, we were brought up, to finish everything on your plate, even when you were literally bursting at the seems, the beliefs we hold about food often stem from our childhood experiences, and this report eloquently describes the neuroscience behind it and giving us back control or at least the choice to either continue eating when full ( I learnt behaviour, for me at least), listen to body and eat with purpose.

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