How the latest nutritional science can help YOU be healthier

Last weekend I went to the most recent conference hosted by the wonderful Mac-Nutrition Collective. Mac-Nutrition always get the most cutting-edge speakers from the world of nutrition, and this event was no exception. It was Stephan Gueynet who took to the stage this time. Stephan is the author of the fabulous book The Hungry Brain, which (in my opinion) is one of the very few nutrition books out there worth reading. Stephan was also recently a guest on The Joe Rogan Experience, and was invited to debate the evidence (or lack thereof) supporting the validity of using low-carbohydrate diets to address the current obesity epidemic.

I thought it might be useful if I gave an overview of the main points from the day. I’m going to keep it as brief as possible in order for you to extract as much benefit from it as possible, but if you would like me to expand on any of the points at all please comment at the end of the post or get in touch via email or Facebook.



Dopamine is our brain’s reward chemical. Some foods trigger a higher dopamine response than others. Those that trigger the biggest dopamine responses lead to higher levels of craving. The foods that tend to trigger the biggest responses are those that are high in both fat and carbohydrates. These are not only problematic in the first instance because they tend to be most calorie-dense foods out there, but they are more likely to lead to us craving more of them, meaning we are likely to eat those calorie-dense foods again and again.

This mechanism led to the success of our ancestors because it rewarded them for keeping themselves well-fuelled. This was vital to the success of our species as to be able to reproduce successfully we needed to be neither too lean or too overweight. Remember also it is only in our species very recent past that acquiring and preparing food has become so easy, and required us to use so few (or no) calories.

Exercise has been found to prevent Type 2 Diabetes

In the past we would have consumed meals high in both fat and carbohydrates very rarely, and when we did the fuel gleaned from those meals would have been put to good use in foraging and hunting for the next such meal. This is backed up by studies of non-industrial populations, who consume hugely calorific meals. They have such active lifestyles and have these meals at such a frequency that there are rarely or no cases of obesity and/or Type 2 Diabetes (which is a disease of lifestyle) in these populations.

In our species’ past foods that delivered us with the highest level of calories offered us the greatest reward. When we ate foods that were rich in carbohydrate, fat, protein, salt or glutamate we experienced a release of dopamine, which in turn made those foods more seductive and meant that we were more keen to seek them out again. This is why we tend to be more addicted to foods that trigger a higher release of dopamine.

The highest sources of calories come from (in order from highest to lowest)

    1. Grain-based desserts

    2. Bread

    3. Chicken dishes

    4. Fizzy drinks

    5. Pizza

    6. Alcoholic drinks

      Some of these are made yet more addictive when combined with substances that offer further reward, such as alcohol and caffeine.


  • Diabetes is the disease most intimately liked to energy balance

  • People who are obese are more likely to be insulin resistant

  • People who are insulin resistant are more likely to have chronic diseases such as cancer, hypertension, coronary heart disease, Type 2 Diabetes and strokes.

  • We all have personal fat thresholds, above which we are more likely to become insulin resistant. In other words the body fat percentage at which we are likely to become insulin resistant varies between individuals. Therefore some people become insulin resistant at lower levels of body fat than others.

  • Genetics is thought to be a factor in our individual level of insulin resistance.

  • Exercise has been found to prevent Type 2 Diabetes.

    • Aerobic exercise by 72%

    • Resistance exercise by 65%

    • Both together by 74%

In our species’ past foods that delivered us with the highest level of calories offered us the greatest reward.


  • Leptin is our bodies’ satiety hormone. It helps our bodies detect when we have eaten enough. It is countered by the “hunger hormone”, ghrelin.

  • Leptin is the most important known signal that regulates body fatness.

  • Since 1994 there have been 33,000 studies proving the effects of leptin.

  • It’s thought by some that leptin is mainly a mechanism for detecting deficiency rather than excess. In other words it is more efficient at detecting when we’ve not eaten enough of something than at detecting when we’ve eaten too much of something.

  • An increase in body fat leads to higher levels of leptin because in obesity the person’s set point has been turned up.

  • There’s definitely some sort of interaction between diet quality and an increase in leptin levels, but this is only based on animal data at the moment. Human research is needed in order for us to get a better understanding of this.

  • Simple unrefined foods lead to high levels of satiety, which means that we need to eat less of them in order to feel satisfied from our meals. This in turn helps keep caloric intake lower.

Weight Loss

  • Our species has a strong incentive for evolving systems that ensure we keep to a healthy weight.

  • Losing and maintaining weight loss takes a challengingly continual level of effort.

  • Whatever a person’s body shape, their body’s mechanisms are constantly fighting to maintain their baseline weight. This is true for lean people, obese people and everyone in between.

  • Regulatory systems can be leveraged for more sustained fat loss (or gain!) using diet and lifestyle strategies

Factors that are suspected to lower our body’s fat set point

    • Simple food

    • High levels of protein

    • Physical activity

    • Possibly restorative sleep

      Our brains receive signals from our gut telling us how full we are via the brainstem. We get higher signals of satiety from foods that are:

    • Calorie dense

    • Taste good

    • Are higher in protein

    • Are higher in fibre

Summary of main points to help YOU be healthier

  • We can control calorie intake by opting for simple, unrefined foods that have been minimally processed.

  • We can allow our brain’s time to forget the reward sensations of foods by going as long as possible without eating them.

  • We can make it difficult for us to snack on foods that trigger a high dopamine response. We could do this by not buying them in the first place, or by keeping those we do have in our homes or workplace out of sight. We could keep them in containers we can’t see into and place them out of eye-line in the fridge, freezer or cupboard.

  • We can ensure that we eat good sources of protein and fibre

  • We can keep active to reduce the likelihood of developing Type 2 Diabetes

I hope you find this post useful. If you have any questions or would like me to clarify anything mentioned here, don’t hesitate to get in touch.

Laura Hilton