Are you caught in the crossfire of diet wars, where one camp swears by low carbs while the other champions low fat?
The truth might lie in the middle. It’s not just carbs or fat alone; it’s the combination of carbs and fat that could be at the heart of the problem.
In the world of nutrition, people often pick sides, forming tight-knit communities that reinforce their dietary preferences. On one side, you have low-carb and keto enthusiasts who believe cutting carbs and embracing fat is the path to health. On the other side, the low-fat advocates argue that excess fat leads to issues like obesity and metabolic syndrome.
But what if the answer isn’t about choosing one over the other? What if it’s about understanding how carbs and fat work together in our diets and finding the right balance for your individual needs?
In this article, we’ll dive into the data to uncover the complexities of carbs and fat in your diet. We’ll explore how these macronutrients affect your appetite, weight, and overall health. By the end, you’ll have a clear roadmap to navigate the dietary maze and make choices that align with your goals.
- Why Do I Care?
- Satiety Response to Carbohydrates
- Satiety Response to Fat
- Carbs vs Fat: Which Causes More Weight Gain?
- Fat AND Carbs
- Step 1: Get Adequate Protein
- What Makes Us Overeat?
- Should I Lower Carbs or Fat to Lose Weight?
- Do Carbs Make You Fatter Than Fat?
- Are Carbs Worse Than Fat?
- So, What Can I Eat?
- Do I Need to Choose One Team?
- Is It Better to Eat More Carbs or Fat?
Why Do I Care?
I’m an engineer. Both my wife and 16-year-old son have Type-1 Diabetes. So, precision in nutrition is critical to help those I love. This is personal.
I also happened to have grown up in a Seventh-Day Adventist (SDA) home until my family decided to leave the church when I was about 10. As you may be aware, the SDAs have played, and continue to play, a significant role in our beliefs about nutrition. For more on the role of the SDA church in nutrition, see The Perils of Belief-Based Nutrition.
I understand what nutritional belief-based dogma looks like from the inside. This experience has made me sceptical of dogmatic dietary solutions.
Over the past two decades, I’ve delved into and experimented with many popular dietary trends as they’ve come and gone. While each has its success stories and true believers, they all have their limitations when they’re over-simplified and taken to the extreme.
I’ve been on a mission to cut through the dogma, conflicts of interest, and beliefs that are endemic in the nutrition space. For me, data = truth.
Fortunately, I’ve had access to some large datasets that have provided powerful insights I try to share with anyone who will listen.
Once we look past the named diets, we can see why each approach works… and why it often eventually fails. We can then use the insights from the analysis to troubleshoot when the wheels fall off.
These days, I have the privilege of guiding people through debugging their current diets with our various programs that guide people to discover what and when to eat. A lot of the time it feels like I’m running a recovery program for people who have found themselves trapped in dogmatic dietary extremes.
In this article, I want to share some of my insights into how you can eat for satiety and crush your cravings without getting trapped at the extremes.
Satiety Response to Carbohydrates
The best place to start is by looking at our satiety response to carbohydrates, which is a topic of relentless debate. Comparing the satiety response of carbs vs fat is crucial for understanding their impact on our eating behaviour.
We created the following chart of non-fibre carbs vs calorie intake using 138,092 days of data accumulated from people who have used Nutrient Optimiser over the past four years.
The first thing to notice is it’s not a straight line. It’s not as simple as eating carbs makes you fat. It’s a bit more complex.
- We eat the most when our diet consists of about 45% non-fibre carbs, and most of the remaining energy comes from fat.
- Sadly, the average population’s carb intake aligns with this maximum calorie intake. Foods like doughnuts, pizza, cookies, and cakes that many consider ‘bad carbs’ are just low-protein, hyper-palatable combinations of fat and carbs. Because these foods simultaneously fill our glucose and fat fuel tanks, we’re more likely to store fat as our bodies struggle to burn off carbs (sugar) and fat. Both fat and carbs elicit a dopamine response, meaning we get a ‘supra additive’ dopamine response when we eat foods that contain both. This, and the blood sugar rollercoaster these foods put you on, can result in feeling ‘addicted to food’ and like you can’t stop eating more of them.
- Interestingly, towards the right, we see that a very high-carb, low-fat diet is harder to overeat. It would be hard to get fat eating only rice and potatoes – it’s when we add oil that we get into trouble.
- Towards the left, we also see that reducing carbs from 45% to 10-20% aligns with a 23% reduction in energy intake.
- There doesn’t appear to be any additional satiety benefit in pushing non-fibre carbs below 10%. Although our bodies can make glucose from protein via gluconeogenesis, we seem to end up eating more because our bodies crave some energy from carbohydrates.
For more on finding your ideal carbohydrate intake, see Carbohydrates – Optimal vs Acceptable Macronutrient Distribution Range (AMDR).
Satiety Response to Fat
The satiety response to fat is much simpler than our response to carbs; it is essentially linear. The higher our fat %, the more we tend to eat. When examining carbs vs fat, the linear satiety response to fat presents a stark contrast to the more complex response observed with carbohydrates.
But at the same time, fat tends to come packaged with high-protein foods like meat, poultry products, seafood, and dairy. So, we can’t slash our fat intake to zero like we can with carbohydrates.
For more on finding your ideal fat intake, see Fat – Optimal vs Acceptable Macronutrient Distribution Range (AMDR).
Carbs vs Fat: Which Causes More Weight Gain?
When we look at the satiety response to non-fibre carbs and fat together, we see they both impact the number of calories we consume.
It’s not really fat or carbs that lead you to eat more. Reducing one or both will increase satiety and help you eat less. We walk our Optimisers through this process in our four-week Macros Masterclass to find a sustainable balance that suits their preferences and context.
Fat AND Carbs
Things become a lot clearer when we look at how we respond to carbs and fat together. The less energy we consume from protein and fibre— the more we get from fat and carbs—the more we eat.
To be clear, the primary reason we eat is to get energy. However, we also require nutrients to build, repair, and provide the resources for all the functions in our bodies. Of all the essential nutrients, we seem to have the most significant demand—and cravings for—protein and the amino acids that make it up.
To the right of the chart, you can see a dotted vertical line showing that the average population’s cumulative fat and carb intake is about 86%. This aligns with the maximum energy intake.
The chart below shows the wide distribution of fat and carb intakes from our Optimisers who are trying to eat for satiety with a more nutrient-dense diet. The average is 63% energy from fat and carbs, with the remainder coming from protein and fibre.
As we progress through our Macros Masterclass, many of our Optimisers only need to increase their absolute protein intake (i.e., in grams) a little to see the results they were hoping for. The majority of the benefit comes from dialling back fat and carbs, which increases their overall per cent of total calories from protein, or protein %.
Step 1: Get Adequate Protein
Like we said, you don’t need to swing from one extreme to the other to increase satiety. Instead, you must dial back energy from carbs and fat while prioritising foods with a higher protein %.
Additionally, it’s ideal if the carbohydrates you eat contain more fibre. Fibre not only indicates that a food is less processed and contains less refined flour and sugar, but it also is a tell-tale that a food may contain more nutrients.
Depending on which camp you belong to, people like to promote or demonise different energy sources. For example:
- Many people with a plant-based background hate on saturated fat and cholesterol.
- Low-carbers limit starchy carbs and sugars and tend to believe they’re the root cause of all diseases.
From our analysis, we saw that:
- Moving from a low to a high intake of saturated fat aligns with a 16% increase in energy intake;
- Moving from a low to high monounsaturated fat intake aligns with a 13% increase in energy consumption;
- Moving from low to high intakes of starch aligns with an 11% increase in overall energy intake; and
- Increasing our sugar consumption aligns with a 7% increase in energy intake.
|Saturated Fat (%)||20.2||62.3||286||16%|
|Monosaturated Fat (%)||14.7||52.1||237||13%|
We need enough energy from our food to supply our bodies with the fuel they need to do their many jobs. But if you add more energy that is devoid of the nutrients your body needs, you’ll eat more.
Not too long ago, foods like nuts and breast milk were the most energy dense carb+fat combo food that enables us to get lots of energy quickly to grow. But more recently, innovative food manufacturers have learned that if we add ALL of these energy sources at once to the same food and remove all the natural nutrients that keep us satiated, like protein, fibre, vitamins, and minerals, we’ll keep on eating and buying more of them!
Because these fat-and-carb combo ‘junk’ foods simultaneously fill our glucose and fat fuel tanks—which would be highly advantageous in primitive times where we’d need as much fuel as we could get to survive—they also overdrive our dopamine circuits, guaranteeing you will never stop at just one.
The simplest way to increase satiety is to avoid processed foods that combine refined grains, industrial seed oils, and refined sugar. A great example is the Oreo cookie, which we can see from the ingredients list, is a combination of starch, sugars, and fat.
If the ingredients need flavours, colourings, and fortified synthetic nutrients, it’s a dead giveaway that they’re bad choices for your waistline and health!
But if you’re seeking out foods that contain the protein and nutrients your body needs, you’ll automatically eliminate these highly engineered Frankenfoods.
Should I Lower Carbs or Fat to Lose Weight?
As mentioned earlier, we can make ATP—the body’s primary energy source—from protein through a process known as gluconeogenesis, but it is highly inefficient. Thus, we are left with fat and carbs as our primary energy sources.
Fat is the most energy-dense macronutrient at nine calories per gram. However, one fat molecule also provides nearly three times the amount of ATP as one glucose molecule. Therefore, we consider it a ‘slow-burning’ source of fuel that keeps us energised in the long term, and it does not spike blood sugar in such erratic ways.
On the other hand, carbs only provide four calories per gram. Although they supply less ATP per gram than fat, they are a volatile fuel known to spike blood glucose rapidly. If you’re an athlete, they’re great for fuelling activity!
Hence, the problem is not fat or carbs; it’s the diabolical combination of fat and carbs that spikes your blood sugar and overfills your fat and carb fuel tanks.
So, which one do we choose as our energy source?
My preference is to start by dialling back your intake of refined carbs until your blood glucose levels stabilise into the normal healthy range. Wildly oscillating blood glucose levels from overconsuming refined carbs can dysregulate your eating pattern and lead to overeating when your blood glucose comes crashing down.
If your blood glucose rises by more than 30 mg/dL (1.6 mmol/L) after eating, it’s a sign you’ve overfilled your glucose fuel tank and didn’t need as many carbs as you ate at your last meal. This is one of the principles we teach in our Data-Driven Fasting program.
However, pushing carbs below 10% of total energy intake doesn’t appear to have any additional satiety benefit. Pushing carbs too low often leads to excessive intake of low-satiety high-fat foods.
While some people believe that fat is the most satiating macronutrient and you can ‘eat fat to satiety’, we know that fat provides very little in the way of vitamins, minerals, and amino acids, which largely influence satiety.
Thus, once your blood glucose is stable and you’ve reduced your refined carbs, it may be better to dial back your dietary fat intake so your body can use the body fat it has stored.
Do Carbs Make You Fatter Than Fat?
Some people think there is something unique about carbs that makes you fat. This belief typically revolves around the Carbohydrate-Insulin Model of Obesity, which believes that carbs raise insulin most in the short term, which leads to weight gain. However, the reality is that insulin can’t store the energy you haven’t eaten!
For more on the carb-insulin model of obesity, check out
- The Carb-Insulin Model vs Protein Leverage Hypothesis, and
- Personal Fat Threshold Model of Insulin Resistance, Diabetes, and Obesity vs the Carbohydrate-Insulin Model of Obesity.
But much like carbs, we know from our work on the food insulin index that fat also elicits an insulin response, but over the longer term. The insulin response to dietary fat is much smaller because it’s easier for your body to store lots of energy as fat.
In time, your body stores excess energy from the fat you ate as body fat, which requires more basal insulin to keep it in storage. Thus, it’s excess body fat that raises insulin levels and not the other way around.
For more details, see Insulin is NOT Making You Fat (and Here’s Why).
Are Carbs Worse Than Fat?
Carbs and fat both contain carbon-carbon bonds that your body can use to create energy in the form of ATP.
Fat is an energy-dense, slow-burning fuel, making it great for storage and everyday use when you’re not doing much intense or strenuous activity.
In contrast, carbs are bulkier and only contain four calories per gram, and you only have around 2000 calories of space to store them in your body. You also retain about four grams of water for each gram of glycogen—the storage form of glucose—that you store.
Carbs are like rocket fuel for metabolism, making them perfect for intense activity. But because of a principle known as oxidative priority and the fact that there is little room to store carbs, your body must use carbs before it can utilise dietary fat and body fat for fuel.
Thus, if you combine fats and carbs or most of your diet consists of a mixture of the two, a lot of the fat you’re consuming will end up stored as body fat.
- To allow your body to use fat, you need to ensure you’re not overfilling your glucose fuel tank.
- But to ensure you’re using body fat, you must dial back the fat in your diet.
It’s also worth mentioning here that alcohol is first in line to be used, even before carbs and fat. The energy from alcohol can easily add up to a large amount. So if you want to use your carbs, fat in your diet and the fat on your body, you may need to keep an eye on your alcohol intake.
So, What Can I Eat?
Unfortunately, most dietary approaches use an all-or-nothing mentality and have you focussing on what you can’t eat. You know, like:
However, our analysis has shown that all these ‘bad’ things tend to look after themselves if we focus on nutrient density and nourishing our bodies with the vitamins, minerals, fatty acids, and amino acids it needs without excess energy.
As we mentioned before, protein intake influences satiety the most. Hence, we eat fewer calories when we get adequate protein without overconsuming energy from carbs or fat.
But protein isn’t the only thing that contributes to satiety; many other essential nutrients that play a role in satiety tend to accompany foods and meals that naturally contain more protein. Thus, the significant satiety effect we see from protein might actually be from this complex of nutrients. For more on this, check out Nutrient Leverage Theory – Cluster Analysis.
Our multivariate analysis of our accumulated Nutrient Optimiser data enables us to dig in and understand what other factors align with greater satiety. The table below shows the results of a multivariate linear regression analysis performed on 111,897 days of Optimiser data. Here, we see a reduced calorie intake when we also pack more potassium, fibre, sodium, and calcium into our daily dietary budget.
|Pantothenic Acid (B5)||4||15||-18||-1.1%|
If we look at the things that align with us eating more AND less, we see that:
- eating more starch and monounsaturated fat aligns with an increased energy intake, whereas
- packing our diet with more protein, fibre, cholesterol and other essential nutrients like sodium, potassium, selenium, B2, and B5 help us feel the most satisfied and keep us from overeating!
|fibre (g/2000 cal)||11||42||-204||-11.5%|
|cholesterol (mg/2000 cal)||235||1,087||-181||-10.2%|
|Potassium (mg/2000 cal)||1,788||5,290||-95||-5.4%|
|Sodium (mg/2000 cal)||1,332||4,359||-77||-4.3%|
|Vitamin B2 (mg/2000 cal)||1.3||4.7||-35||-2.0%|
|Selenium (mcg/2000 cal)||65||252||-23||-1.3%|
|sugar (g/2000 cal)||12||71||5||0.3%|
|starch (g/2000 cal)||0.9||50||73||4.1%|
|monosaturated (g/2000 cal)||17||53||86||4.9%|
Yes, you heard me right! It appears that foods that naturally contain cholesterol, like eggs and liver, are more satiating. Because we have intense cravings for sodium, we’ll continue eating until we get enough of it, too. Hence, actively avoiding these foods that contain these nutrients may actually make us eat more!
Do I Need to Choose One Team?
Most people gravitate to team low-carb or team low-fat depending on their pre-existing beliefs. However, we don’t believe that’s really necessary.
If you’re getting adequate protein and staying within your energy budget, it doesn’t matter much if you prefer to get most of your energy from carbs or fat. It can even be useful to mix things up across the day or depending on your energy requirements.
In our Data-Driven Fasting Challenges, people who eat a lower-carb diet tend to see higher glucose levels in the morning and lower readings in the afternoon. This is illustrated in the example from our Data-Driven Fasting app below.
People with this blood sugar pattern often find it easier to wait to eat because they already have plenty of energy in their bloodstream. However, they end up overeating at night because their blood glucose drops, prompting hunger.
A ‘hack’ that many have found useful is to focus on protein at the first meal. Because protein comes packaged with fat, someone will experience greater satiety and more stable blood glucose throughout the day.
If their blood glucose is lower than normal later in the day, they can add protein and carbohydrates instead of fat to bring their glucose back into the normal range. This will help them avoid overeating. By doing this, someone can have more foods in their repertoire and satisfy their appetite based on their body’s needs. The key is to ensure you are hungry and your glucose tank is depleted before adding extra carbohydrates.
Additionally, you may consider adding a little carbohydrate before or after your workout if you’re doing a lot of intense activity and your blood glucose is often depleted. On the other hand, if you’re not so active, you will need less carbs.
Is It Better to Eat More Carbs or Fat?
With two people with Type-1 Diabetes in the family, I’ve seen how powerful limiting carbohydrates can be for stabilising blood glucose levels. This leads to better appetite control, improved mood, focus, clearer cognition, and more consistent energy levels, amongst other things.
This is not just relevant for people with diabetes; anyone who is obese or trying to lose weight likely has some insulin resistance, which results in higher glucose levels after eating.
Testing your glucose with a simple glucometer before and one hour after you eat is a super simple way to understand if you’re overconsuming carbohydrates. You will quickly be able to identify the foods and meals that raise your glucose the most so you can reduce or eliminate them in the future.
While dialling in your carbohydrate intake, you don’t need to fear fat. However, calories in must equal or be less than calories out to avoid weight gain. Hence, you’ll have a better outcome if you prioritise protein rather than believing you can ‘eat fat to satiety’.
Once your glucose stabilises and you stop losing weight, your next step is to reduce your dietary fat intake while still prioritising protein. This will allow your body to use fat for fuel instead of dietary fat, meaning the fat-loss process can continue.
- Fat or carbs are not the problem; it’s the combination of fat and carbs in ultra-processed foods that lead you to eat more than you need.
- Reducing your intake of fat or carbs while prioritising protein, as we do in our Macros Masterclass, will increase satiety and help you eat less.
- If you are obese, you likely have some degree of insulin resistance. So, you could start by limiting or eliminating higher-carb foods that raise your blood glucose by more than 30 mg/dL (1.6 mmol/L) after eating them.
- Once your glucose is stable, your next step is to dial back your dietary fat intake. This will enable your body to use your stored body fat for fuel.
- Supplying your body with the nutrients it requires while staying within your energy budget will allow you to regain control of your appetite and optimise your metabolic health.
- Personalised Satiety: Optimising Satiety for Low Carb vs Low Fat
- Ultra-Processed Foods: What’s the Problem and How to Avoid Them
- Low-Carb vs Low-Fat: What’s Best for Weight Loss, Satiety, Nutrient Density, and Long-Term Adherence?
- The Carb-Insulin Model vs Protein Leverage Hypothesis
- Oxidative Priority: The Key to Unlocking Your Body Fat Stores
- The Perils of Belief-Based Nutrition
- Manifesto for Agnostic Nutrition – Beyond Belief-Based Named Diets
- Macros Masterclass