Book review – Wired to Eat by Robb Wolf

Please note this post does not in any way constitute medical or dietary advice. It is simply my review of a book and the personal experimentation I have conducted.

Wired to Eat by Robb Wolf is a great read. Robb Wolf is probably more commonly known as the Paleo Guy with his hugely popular podcast The Paleo Solution and the New York Times bestselling book of the same name.

I know many people roll their eyes at the sight of the word Paleo, but Wired to Eat, isn’t a book aimed at solely converting you to a Paleo diet, it is a book that encourages and educates you to find out what foods work best for you and explores in detail the concept of Personalised Nutrition.

Wired to Eat is divided into two parts. The first part provides an excellent background on genetic and environmental factors, such as sleep, stress, hyperpalatable foods and community, that make it easy for us to over eat and introduces the concept of Personalised Nutrition. The second part then helps you determine the foods that are right for you and it does use the Paleo diet as a base, but Wolf encourages you to work from that to see what foods are going to serve you best.

The first part of the book does deal with a lot of the science behind eating and nutrition, but it is explained in a way that it is easy for those of us with non science backgrounds to understand. My key takeaways from this part were:

Genetic and environmental factors

  • Our environment has changed significantly but the human body hasn’t caught up – access to food is easier, we move less, but we are still wired to eat.
  • All beings on the planet have an optimum foraging strategy (OFS).
  • OFS is a pattern of movement that tends to maximise the amount of calories and nutrition an individual obtains while minimising the amount of energy expended to do so.
  • The genetics of our OFS expects that getting food will take a significant amount of energy and that there will be times of food scarcity.
  • The reality is that food is easy to access and it requires very little exertion of energy.

Sleep

  • On average Americans are sleeping 2.5 hours a day less than they did in the 1970s.
  • Lack of sleep has significant health impacts as it:
    • impairs insulin sensitivity
    • increases gut permeability
    • increases systemic inflammation
    • impairs immune function
    • alters anabolic hormones
    • causes cravings
    • causes cognitive impairment
  • The less sleep you get, the more important it is that you eat well and in particular manage the carbohydrates you eat.

Stress

  • When the body is under stress, the adrenal glands can trigger the release of glucose stored in various organs, which often leads to elevated levels of glucose in the bloodstream.
  • It may take  longer for glucose levels to return to normal after a meal if you have been stressed.
  • Not all stress is harmful, so we need to reframe our perceptions of what we think is stress.

Hyperpalatable foods

  • The neuroregulation of appetite (the natural process of our brain telling us whether we are hungry or not) is impacted by the huge range of hyperpalatable foods.
  • Within the optimum foraging strategy (OFS) their is a concept called palate fatigue – this is when we get tired of the taste of a particular food.
  • Palate fatigue was an inbuilt safety mechanism for humans to prevents us from eating too much of any plant that could be toxic to us in large amounts and to ensure that we would have an optimum nutrient intake of vitamins and minerals.
  • Processed foods now are engineered for overeating that override palate fatigue. These foods produce a degree of stimulation in the brain that makes unprocessed foods seems less appealing.

Community

  • Lack of human interaction appears to pose a stress to our system.
  • Studies have shown that social isolation can have as big as an impact on our health as smoking, being over weight or excessive alcohol consumption.

Personalised Nutrition

Personalised Nutrition forms the basis for the rest of the book and for the testing protocol Wolf details in part two of the book. Wolf cites a paper which he believes to be one of the most important research projects into nutrition in the last 50 years – Personalized Nutrition by Prediction of Glycemic Responses. The abstract of the study is as follows:

Elevated postprandial blood glucose levels constitute a global epidemic and a major risk factor for prediabetes and type II diabetes, but existing dietary methods for controlling them have limited efficacy. Here, we continuously monitored week-long glucose levels in an 800-person cohort, measured responses to 46,898 meals, and found high variability in the response to identical meals, suggesting that universal dietary recommendations may have limited utility. We devised a machine-learning algorithm that integrates blood parameters, dietary habits, anthropometrics, physical activity, and gut microbiota measured in this cohort and showed that it accurately predicts personalized postprandial glycemic response to real-life meals. We validated these predictions in an independent 100-person cohort. Finally, a blinded randomized controlled dietary intervention based on this algorithm resulted in significantly lower postprandial responses and consistent alterations to gut microbiota configuration. Together, our results suggest that personalized diets may successfully modify elevated postprandial blood glucose and its metabolic consequences. {source}

In essence this means that individuals can react very differently to particular foods even when all other factors are similar.

The 7 day carb test

The book has a couple of chapters on doing a 30 day diet reset before you do a 7 day carb test. It details why you need to do this, how to do it along with recipes and menu plans to help you with it. My diet was already made up of the foods Wolf recommends, so I didn’t do the reset.

I did do the however do the 7 day carb test! The aim of the test is to see how well my body is handling particular types of carbs. This is important for overall health as outlined by the Harvard School of Public Health:

When people eat a food containing carbohydrates, the digestive system breaks down the digestible ones into sugar, which enters the blood.

  • As blood sugar levels rise, the pancreas produces insulin, a hormone that prompts cells to absorb blood sugar for energy or storage.
  • As cells absorb blood sugar, levels in the bloodstream begin to fall.
  • When this happens, the pancreas start making glucagon, a hormone that signals the liver to start releasing stored sugar.
  • This interplay of insulin and glucagon ensure that cells throughout the body, and especially in the brain, have a steady supply of blood sugar.

Carbohydrate metabolism is important in the development of type 2 diabetes, which occurs when the body can’t make enough insulin or can’t properly use the insulin it makes.

  • Type 2 diabetes usually develops gradually over a number of years, beginning when muscle and other cells stop responding to insulin. This condition, known as insulin resistance, causes blood sugar and insulin levels to stay high long after eating. Over time, the heavy demands made on the insulin-making cells wears them out, and insulin production eventually stops.

The 7 day carb test requires you to use a blood glucose monitor to measure blood glucose levels (BGL) before and after the first meal of the day. Blood glucose levels are measured in millimoles per litre of blood (mmol/L) in Australia and that was the reading my glucose monitor gave. As Robb Wolf is American the measurements he notes in the book are (mg/dL).  The Baker IDI says that the normal range for fasting BGL is less than 5.5 mmol/L.

For seven days while eating food along the 30 day reset diet, you test your blood first thing before you eat or drink anything. You note your result and then eat 50 grams of effective carbs. The book has a list of what 50 grams of effective carbs means in reality, for example, it equates to 180 grams white rice or 250 grams banana. Then two hours later you test your blood again.

The testing needs to be done to as close to the exact same circumstances as possible. If you have a glass of water first before your food on day one, then you need to do that on all days. In between testing you don’t eat anything else and if you exercise you need to make sure you do the exact same thing each day otherwise it can distort the results. I found it easier to just move my exercise session to later in the day for the week of testing

My 7 day carb test results

I learnt a significant amount from the testing. The results from these tests don’t mean I cannot eat certain foods, but it provides me with information on how to best incorporate these foods into my diet:

  • All of post meal testing results where within the normal range for BGL, so I am someone who seems to respond pretty well to most carbs. This is consistent with how I personally feel too. I have tried low carb before and found that it wasn’t the best fuelling strategy for me.
  • There were no huge spikes from any food with the highest increase being +0.9 mmol/L for basmati rice.
  • On some post meal testing my BGL results saw a decrease – still trying to work out what this means!
  • I could see there was a direct relationship with less sleep and higher BGL levels. There were two nights where I had less sleep due to being out and my fasting BGL was 1.4mmol/L higher than when I had at least seven hours sleep.
  • The hyperpalatability of food is a real issue. When you eat the carbs for the test they need to be pure carbs – no salt, no fat, no spices etc. It is much harder to eat 50 grams of effective carbs from white potato like this!
  • Eating 50 grams of effective carbs via bananas saw no increase in my BGL.
  • The increase in my BGL was higher with sweet potato (+0.7 mmol/L) compared to white potatoes (+0.1 mmol/L).
  • I responded well to carbs from oats. I tested both steel cut and rolled oats and they were -0.6 mmol/L  and -0.1 mmol/L respectively.
  • My response to buckwheat was better than oats (-1.2 mmol/L).
  • My response to basmati rice was higher than that of potatoes (+0.9 mmol/L).
  • I responded well to sour dough bread with a decrease in BGL (-0.9 mmol/L).

I haven’t made any huge changes to the way I eat since testing but just a few small tweaks:

  • Eating white potatoes more often.
  • Having sour dough as a Sunday breakfast more often.
  • Aiming for brown rice if I am going to have rice.

In summary

Wired to Eat is a valuable book and I highly recommend reading it and giving the 7 day carb test a try. It was great to see a book that took a whole approach to diet:

  • Get good sleep
  • Develop a resilient mindset towards stress
  • Nurture meaningful relationships
  • Move every day
  • Eat unprocessed food that works for you

Have you done the 7 day carb test?

Some of the links contain affiliate links, which means at no extra cost to you, making purchases through them helps support this site. Thank you!