The reason we eat more of one food than another is complex. Fundamentally, your appetite is driven by your innate survival instinct (rather than your desire to see your abs or look good naked).
When you’re starving hungry, you instinctively know what foods will help you refuel quickly. Rather than broccoli and chicken breast, we reach for our favourite energy-dense “comfort foods”.
But if you want to find a way to eat less without fighting against your hunger monster, you need to find the foods with the higher satiety to calorie ratio.
Why we keep getting it wrong
Countless studies have tried to understand why we overeat. But, unfortunately, they are rarely helpful.
- Controlled human feeding studies provide limited information due to their short duration and lack of resemblance to how we live and eat in the real world.
- Nutritional epidemiology has done little to separate bias, ethical convictions and beliefs to identify practically applicable scientific principles of nutrition.
- Then, discussions about satiety and satiation often get bogged down in our limited understanding of hormones and complex theories that are hard to validate and practically apply in the real world.
- Then there are the extreme diets (e.g. low carb, low fat, plant-based and carnivore) that work because they exclude the most hyperpalatable nutrient-poor comfort foods rather than being nutritious or satiating.
But now, with the widespread use of food tracking apps, we can identify the properties of our food that help us to reduce our intake and tame our hunger monster rather than forever being a slave to our appetite.
Rather than taking a top-down approach that tries to understand why things work, we can take a bottom-up approach and simply look at the habits of the people that align with the outcomes we want and copy that.
What is satiety?
By definition, satiety is the feeling of fullness after a meal. A satiating meal will make you feel full with less energy and stop you feeling hungry for longer.
The Holt Satiety Index of Foods Chart
Perhaps the most useful study ever undertaken in this area was A Satiety Index of Common Foods (Holt et al., 1995).
Researchers fed 1000 kJ of 38 different foods to participants and measured their perceived hunger every fifteen minutes over the following three hours. They also measured the amount of food they ate at a buffet three hours later.
The results are shown in the satiety index chart below. White bread was given an arbitrary score of 100% (anything with a score higher than 100% is more satiating per calorie than white bread, and vice versa).
Unfortunately, the satiety index chart is hard to make much sense of, so we did some further analysis to see which parameters align with satiety.
Satiety index vs energy density
Energy density is the weight of food per calorie. Previous works such as Barbara Rolls’ Volumetrics Eating Plan have identified that foods with more volume and weight per calorie tend to be more filling.
The chart below, which plots the Satiety Index of Foods data vs their energy density, shows that foods with a low energy density like oranges and grapes tend to be more satiating.
Satiety index vs protein
Although only a couple of high protein foods were tested (i.e. steak and fish), the satiety index of foods data indicates that foods with more protein tend to be more satiating.
Satiety index vs fat
This is where things get a little more interesting. Like many things in nature, the relationship between fat and satiety tends to follow a ‘u-shaped curve’. We see that:
- very low-fat foods are harder to overeat.
- higher fat foods like egg and cheese are more satiating than those that are a combination of fat and carbs together.
- foods that are a mix of fat and carbs (e.g. cake and doughnuts) are the least satiating.
Satiety index vs total carbohydrates
Some people prefer a low-fat diet, while others swear by low carb to lose weight.
The plot of the Satiety Index Foods data vs carbohydrates shows that:
- high carbohydrate low-fat foods are hard to over-consume,
- low carbohydrate high protein foods (like steak and fish) are satiating, but again
- it’s the fat+carb combo that is hardest to resist.
Foods with more fibre tend to be harder to overeat. Foods with more water and fibre fill us up and lead to ‘early satiety‘.
Satiety index vs starch
The next chart shows the relationship between starch and satiety. We see that:
- very high starch (without added fat) are hard to overeat,
- low starch high protein foods are satiating, and
- it’s the foods that are a mixture of fat and starch that are easy to overeat.
It’s worth noting here that the star performer in the satiety study was the plain boiled potato. People found it filling and hard to eat much at the buffet three hours later. This could be due to the low palatability of plain potatoes or the effects of resistant starch which forms when we cook and cool potatoes before eating.
You may have heard of the Potato Hack Diet where people eat nothing but potatoes and lose weight. Unfortunately, while satiating, plain potato is not the most nutrient-dense and may not provide enough protein to maintain high levels of lean muscle mass during weight loss. You would also need to eat it without added fat (e.g. butter, oil, etc.). Otherwise, it’s extremely easy to overeat (e.g. chips).
Satiety index vs sugar
Sugar is blamed for a lot of things. However, it appears that sugar in whole juicy fruit is actually quite satiating. Whereas foods with sugar added as an ingredient have a very low satiety value.
Limitations of the laboratory data
While this controlled laboratory study provides some interesting insights, with only 38 data points, there is not really enough information to accurately predict the satiety effect of different foods not yet tested in the lab.
Enter BIG DATA
Recently, my Nutrient Optimiser partner Alex Zotov stumbled across a massive data set of MyFitnessPal food logs that have given us some fascinating insights into what helps people to manage their appetite with less hunger. The data we used is from a ResearchGate publication MyFitnessPal Food Diary Dataset by Weber, Ingmar & Achananuparp, Palakorn (2016).
The authors ‘scraped’ the public food diaries to compile an anonymised database of 587,187 days of food diaries logged by 9,900 MyFitnessPal users who had been recording for more than two months. This is more than 1600 person-years of food diaries! Excitingly, this data allows us to validate the 1995 Holt laboratory data and build a more accurate satiety index.
Which macronutrient best promotes satiety?
We calculated the users’ recorded calories divided by their goal intake as a measure of satiety.
- If this number is higher than 100%, it means they reported consuming more than they planned to for the day.
- If this number is less than 100%, then they recorded consuming less than they planned for the day.
This measure of satiety can be then plotted against the other parameters such as protein, fibre, carbs, fat, starch and sugar.
Protein and satiety
People who reported eating more protein are typically more successful in consuming less than their calories target.
It’s important to understand that this is not a matter of eating more protein, but rather foods with a higher percentage of their energy from protein. As we move toward the right, we get ‘leaner’ protein foods with less fat and more energy from protein. This observation aligns with other research indicating that higher levels of protein lead to greater satiety.
The average protein intake for Americans is less than 12%. This coincides with the level where the satiating effects of a higher percentage of protein intake start to take effect. Left to our own devices, it seems that we optimise our diet for maximum energy intake. Since the 1977 Dietary Goals for Americans recommend that people cut back on saturated fat and cholesterol, the percentage of protein has decreased.
The frequency distribution chart below shows that very few people manage to consume a diet with more than 40% protein consistently.
The next chart of fat vs satiety response shows that we tend to eat less when we consume less than around 40% of our calories from fat.
Traditional cultures that lived on a diet of rice and vegetables (without added oil) tend to be lean and long-lived (e.g. the Kitavans and Okinawans). However, given the opportunity, we tend to gravitate to a similar mixture of fat and carbs, which enables us to consume more energy.
The chart below shows the plot of the percentage of carbohydrate vs satiety. In the centre of the chart, we see that on a calorie for calorie basis, foods that are a mixture of fat+carbs tend to be the easiest to overconsume.
We get an improvement in satiety when we reduce carbohydrate intake and move away from the carb+fat danger zone of food combinations that do not occur in nature.
Many people report a spontaneous reduction in appetite when they reduce the carbs in their diet. However, it appears that the benefit of a low carb high-fat diet comes from the lowering of carbohydrates rather than a focus on high fat.
When we move further to the left, we get a higher energy density and less fibre, so the appetite suppressing effects of a low carb diet diminish. A very low carb diet also tends to be less nutritious. Analysis of our series of 22 recipe books indicates that maximum nutrient density aligns with around 15 – 20% carbohydrates.
On the far right of the carb vs satiety chart we see that very high carb, low-fat foods are tough to overconsume. This aligns with what we see in people who follow a strict whole food plant-based dietary approach (without added oils). However, the frequency distribution chart shows that few people are actually achieving the appetite suppression benefits of a high carb low-fat diet, which would occur above 60% carbs.
Data from the USDA Economic Research Service shows that, with increased food processing, our diet has trended towards a similar level of fat and carbs.
This mixture of fat and carbs enables us to consume more of the hyperpalatable processed foods that food manufacturers are eager to sell us. Our growing obesity levels have risen in parallel with an increasing supply of this type of food.
Similarly, people in China have doubled their calorie intake as they have added more cheap vegetable oils to their diet.
This has resulted in a similar increase in obesity rates that we see across the world.
Similar to the 1995 Holt study, foods with more fibre tend to be more satiating.
Foods with moderate levels of starch are easier to binge on while foods with a lot of starch and very little fat seem to be slightly more satiating.
But, not many people eat more than 50% starch, so we don’t know what happens when people eat a very high starch diet.
Lastly, sugar seems to have a positive effect on satiety. While sugar raises insulin more than fat in the short term and makes foods more palatable, it seems that high sugar fruits can be more satiating (at least relative to high-fat foods).
Foods that are naturally high in sugar often have a lower energy density which makes them harder to overconsume. Holt et al., in another paper discussing their data, noted that foods that raise our insulin more in the short term actually tend to promote satiety.
Due to concerns around excess High Fructose Corn Syrup in soft drinks and the approval of artificial sweeteners like Splenda in 1999, Americans have significantly decreased their sugar intake this century. In spite of this, the obesity epidemic has continued to march on. While foods with added sugar are likely not the most nutritious choice, it doesn’t appear that sugar is the primary culprit for the obesity epidemic.
The best and worst macronutrient combinations
While this analysis has shown the satiety response to a range of food parameters, we don’t consume macronutrients in isolation. Foods come packaged together. We never eat foods that are 100% protein, 100% carbs or 100% fat.
So I thought it would be interesting to look at combinations of nutrients in order to understand which ones we should avoid versus the ones we should prioritise for different goals.
The chart below shows the satiety response of the food combinations with the most significant positive effect (i.e. protein+fibre) and negative affect (i.e. starch+fat).
Fat + starch
Reducing the energy from fat and starch appears to be the most useful thing you can do to manage your appetite.
Regardless of willpower and dedicated weighing and measuring, we will likely struggle to maintain a sustained calorie deficit when we eat these foods. It’s the “comfort foods” like crackers, doughnuts, cookies and lasagne that you will go back to for seconds and not stop until they’re all gone.
Today, the combination of starch and fat makes up a large portion of our energy intake. But this wasn’t always the case. As a general rule, foods that are a mixture of fat and starch do not occur in nature!
Wheat and corn are typically harvested in summer and autumn. Before modern agriculture and refrigeration, we would have relied more on high-fat animals during winter (at least in temperate climates away from the equator).
Whether by luck or design, the food industry seems to understand the hyper palatability of fat+starch. It’s the added fats and flours that have increased the most in parallel with the growing obesity epidemic.
If weight loss is a goal, you should try to reduce the foods and meals that contain starch (e.g. wheat flour and cornstarch ) and added fats (e.g. canola, soy oil and rapeseed oil ) as ingredients, especially together.
This chart shows the satiety response from the combination of fat + carbs, which is nearly as diabolical as starch + fat. Once we get beyond about 65% of energy from fat+carbs, your hunger will ramp up, and you will consume more energy.
Protein + fibre
But the best form of defence is an offence. Rather than merely avoiding “bad foods”, this chart shows the foods with more fibre and protein that will provide greater satiety.
These are the types of foods that are naturally available in spring that someone following a Protein Sparing Modified Fast style diet would consume. Rather than just avoiding hyperpalatable fat+starch, these foods will provide you with the nutrients you need with less hunger. The meme from Optimising Nutrition advisor Dr Ted Naiman sums this up nicely.
The Optimising Nutrition Satiety Index
The primary goal of this analysis was to refine the Nutrient Optimiser algorithm to identify optimal foods and meals for different goals. We combined the various satiety relationships described above into one formula to calculate the Nutrient Optimiser Satiety Score.
The chart below shows that we get a strong correlation between our Nutrient Optimiser Satiety Score and the laboratory satiety data from the 1995 University of Sydney laboratory study for the 38 foods already tested.
The R2 of 0.6 indicates that the new satiety score using the MyFitnessPal data provides a good correlation with the laboratory satiety data. We can now identify foods that will maximise satiety and help maintain a healthy weight with less hunger, deprivation and less reliance on willpower.
Satiety index vs nutrient density
The satiety data is even more useful when combined with nutrient density.
The chart below shows satiety vs nutrient density. Foods towards the top right of the chart will be more nutritious and more satiating.
To look at the data in more detail, click here.
This chart shows satiety vs nutrient density for plant-based foods. Processed grains are clustered towards the bottom left corner while vegetables are generally towards the top right and legumes towards the centre.
To look at the data in more detail, click here.
The chart below shows the animal-based version of the nutrient density versus satiety chart. Egg whites are the most satiating option. However, shellfish towards the top right of the graph will provide high levels of satiety and nutrient density.
To look at the data in more detail, click here.
Free satiety index food list
Now, by combining our satiety index with nutrient density, we can identify the foods that will provide greater satiety and all the essential nutrients you need. You can download a free foods list optimised to suit your goal and preferences here.
Nutritious recipes optimised for fat loss
But finally, the real magic happens when we combine these foods into recipes that contain all the nutrients you need while also maximizing satiety for fat loss for less hunger which you can learn more about here.