How do carbs, fat, sugar, alcohol and starch stimulate your appetite?

Welcome to the second part of our series looking at the key factors that influence satiety and how the type of food you eat will affect how much you eat.  

Following on from our first article on protein, this article looks at the satiety effect of fibre, carbs, fat, sugar, energy density, alcohol and water.

About the charts

The charts in this article are based on the analysis of more than forty thousand days of data from more than a thousand Optimisers. 

The horizontal axis is the proportion of energy from each source, while the vertical axis is the calories consumed divided by the individual’s basal metabolic rate (BMR). 

A higher number means that people generally eat more while a lower number means that the majority of Optimisers ate less.


As shown in the chart below, a larger intake of carbohydrates correlates with a higher energy intake.  People who ate more carbohydrates consumed more than 15% more than those who ate less.

The analysis of non-fibre carbohydrates (i.e. total carbohydrate minus fibre) shows a similar trend.  

However, we need to keep in mind that this data is taken from people who are typically following a lower carbohydrate dietary approach.  The average carbohydrate intake of these Optimisers was 15% compared to the average population intake of 44%. So we can’t rely too much on the data to the very high carb end because there were not a lot of people following a very high carb diet (as shown in the carbohydrate distribution chart below).    

In our satiety analysis using MyFitnessPal data, we found that a very low-fat high carb (i.e. greater than 60%) diet is hard to overconsume. 

Rather than avoiding all carbohydrates, a good rule of thumb to manage your hunger seems to be to avoid foods that are combinations of fat and carbohydrates.  These foods are rare in nature but essentially the formula for modern processed junk food.  

Few people are able to maintain a diet with greater than 60% carbohydrates.  Most of the time, we gravitate to a mixture of carbs+fat between the two extremes that minimises satiety and allows us to consume more food.  

The laboratory data from A Satiety Index of Common Foods (Hold, 1995) also indicate that a high carbohydrate intake without fat (e.g. plain rice, fruit, potatoes) tend to be more satiating than foods that are a mixture of carbs and fat.


Similar to carbohydrates, people who eat a higher percentage of fat tend to eat around 15% more than those who ate the least fat.   

This also aligns with our previous MyFitnessPal analysis, which showed that once we separate fat from protein, fat as a macronutrient is not particularly satiating.  

Again, this observation that higher fat foods tend to have a lower satiety response aligns with Holt laboratory satiety data.  

It appears that consuming ‘fat to satiety’ is dangerous if your goal is fat loss! 


The chart below shows the satiety response to the combination of fat and non-fibre carbs.  

  • Reducing the proportion of energy from fat+net carbs from 75% to 57% corresponds with an 18% lower energy intake.
  • If your goal is to lose body fat, a sensible stretch target would be to get less than 55% of your energy from the combination of fat and non-fibre carbs.  
  • Conversely, if you were trying to gain weight, a reasonable stretch target would be to get around 75% of your energy from carbs and fat (i.e. similar to the current average population intake). 

It’s remarkable how we instinctively optimise our food choices to maximise calorie intake when we have the opportunity.


While fibre does have a positive impact on satiety, it’s small compared to protein.  There is no real need to go out of your way to prioritise fibre if you are following a nutrient-dense diet.   Not many people can push their fibre intake to levels that correspond with a significant increase in satiety.

Energy density 

Heavier foods with more water and fibre and fewer calories tend to be harder to overconsume.  This data from Optimisers indicates that energy density correlates strongly with lower energy intake.  People who eat foods that are less dense eat around half as much as those who eat the most energy-dense foods and meals.

However, we tend to gravitate towards denser foods.  Not many people sustain a lower energy density that leads to improved satiety. Practically, it’s challenging to consume a diet with a low enough energy density that will have a meaningful impact on satiety.


While naturally occurring sugar in fruits and vegetables aligns with a nutrient-dense whole food diet, consuming more than around 20% sugar tends to increase our overall calorie intake.  

While avoiding added sugar is a good idea to improve nutrient density and satiety, it does not appear that sugar is a significant factor that affects our satiety at the levels we find in whole foods.   

Our consumption of added sugars has decreased since artificial sweeteners started to replace high fructose corn syrup in 1999.  Despite this, obesity rates have continued to rise.

While it’s smart to avoid processed foods that contain refined sugar as an ingredient, it’s not the only factor that we need to consider.


Foods with a small amount of starch as an ingredient tend to align with increased calorie intake up to about 15%.  However, as we push starch intake higher (i.e. without any added fat), we find that these foods are tough to overeat.

The analysis of the MyFitnessPal data also indicated that it may be harder to overeat foods with a high amount of starch without added fat.  Doughnut and chips are very easy to overconsume. However, we don’t tend to binge on plain potato or oats (unless we add honey or sugar).

While there are people thriving on low carb diets that avoid starch, there are also dietary subcultures thriving on high starch intakes (as long as they don’t contain added fats).   


The data shows that when we have a little alcohol, we tend to eat a lot more. This is likely due to reduced inhibition and self-discipline. 

However, if alcohol makes up a very large proportion of your energy intake, you may eat fewer calories than if you drink only a little.  It’s hard to know though whether this is due to the higher oxidative priority of alcohol driving increased satiety or due to nausea/passing out from drinking straight spirits!

Image result for alcoholic

Before Atkins, there was The Drinking Man’s Diet which consisted of eating nothing but steak while drinking a bottle of wine a day. It seemed to work for weight loss (plenty of protein for satiety).  However, intentionally trying to get a lot of your energy from alcohol would be questionable in terms of nutrient density or the ability to hold down a day job if you were always drunk and/or hungover.

Water content 

Most people should drink more water. But because it doesn’t contain calories, people don’t tend to log their water. But they do log their lattes, sodas and alcohol. The chart below shows that caloric beverages don’t register much of a satiety response.

Although fruit and vegetables tend to be bulky and hard to overeat because they have a lower caloric density, sodas and juices will NOT help you stay full or within your caloric target. Calories from drinks can add up very quickly.

The take-home message here is that you should ideally chew your food and drink your water.   Minimise drinks that contain a significant amount of calories if your weight is important to you.

Comparison of satiety response

To bring all this together, the chart below shows the satiety response curves for the most significant factors that affect satiety.

Fibre has a small positive impact on satiety, while fat and carbs are negatively correlated.  The most dominant factor by far is the protein percentage, which has the most significant potential to influence how much you eat.  To simplify this, the chart below shows protein vs energy from carbs and fat together.  

A greater percentage of protein has the highest positive impact on satiety.  But you can also think of this in terms of less energy from carbs and fat. This overall trend aligns nicely with our previous data analysis of half a million days of My FitnessPal data (shown below). 

Stretch targets

To help you out this into practice, the table below lists the various factors that affect satiety ranked from largest to smallest effect.  Also included are:

  • the population average intake,
  • the average intake for Optimisers (who are generally targeting a more nutrient-dense diet), and 
  • a suggested stretch target for each of the parameters if you are looking to improve satiety and lose weight  
nutrient population averageOptimiser averagestretch target (fat loss)
protein (%)12%28%> 40%
protein + fibre (%)14%33%> 45%
fat + carb (%)88%72%< 60%
carbs (%)46%20%
fat + net carb (%)76%66%< 50%
net carbs (%)34%15%
fat (%)42%52%< 35%
fibre (%)2%5%> 8%

If your goal was to improve satiety, eat less and lose weight you could:

  • Progressively titrate up your protein intake towards 40% of your calorie intake (or higher).
  • Reduce your carbohydrate intake to the point that your blood sugars stabilise.
  • Decrease the combination of your energy from fat and carbs intake to less 60%.
  • Dial down your fat intake to 35% or less.  

Where do I start?

After four years of digging into the theory, we’ve created some exciting tools to help you implement the theory. We’d love you to check them out!

Keep reading

In our next article in this series, we’ll be looking at how the various fatty acids (i.e. cholesterol, omega 3, polyunsaturated, monounsaturated and saturated fats) drive you to eat more or increase your satiety and help you to eat less.

To kickstart your journey towards optimal get your free program and one of 70+ food lists personalised just for you!  

Marty Kendall