By Lindsay Wilson
The best foods for weight loss are the ones that fill you up
Back in 2010 a nutrition professor from Kansas State University decided to prove to the world that energy balance is what determines weight loss by going on a ‘twinkie diet’. He ate less than 1,800 calories a day of largely junk food, lost 27 pounds (12kg) of weight, reduced body fat by 10% and improved his cholesterol profile. He succeeded in reminding people that calories matter for weight loss, but added to the noise.
This supreme piece of headline baiting triggered yet another round of the ‘quantity vs quality’ wars you see in the world of online nutrition from time to time. These ‘wars’ are good fun for headline writers but seriously, it’s like asking me if I want to educate my kids or feed them? It is a false dilemma. Not only should you care about both the quantity and quality of the food you eat, you should understand quantity and quality are intimately linked.
In this second section of The Fat Loss Framework we are going to look at why eating ‘filling foods’ makes maintaining a caloric deficit easier. We’ll start by looking at the type of foods that can promote overeating, and then work through five food groups that can help you maintain a deficit: lean protein, colourful vegetables, natural fats, watery carbs and juicy fruit. We’ll then finish by touching on the importance of flexibility.
The diet that makes us fat
I hate the phrase ‘fattening food’. I think it promotes the false notion that individual foods will ‘make you fat’ and can make weight loss harder than it needs to be by encouraging unnecessary food restrictions. Instead I prefer to think of ‘fattening diets’, that is the type of diet where it’s easy to find yourself in a caloric surplus and thus gaining weight.
One diet in particular stands out as fattening. We often call it the ‘Western Diet’ or the ‘Standard American Diet’. It’s basically a diet high in cheap calorie dense processed foods. As this diet spreads throughout the world obesity rates seem to follow it. It’s also the driving force behind the biggest uncontrolled overfeeding study the word has ever seen, America.
In the forty years between 1970 and 2010 the average American’s daily caloric intake has increased by around 500 kcal a day (about 1 Big Mac). In the same period obesity rates have risen considerably. You can see the striking correlation in the graph below.
What this graph shows is that a rise in caloric intake in the US population over the last 40 years is strongly correlated with rising obesity rates. This doesn’t prove that Americans eating more calories is causing the obesity problem, although there are studies that support this view, but I think it’s safe to say it’s clearly part of the problem.
The big question is why? It’s not like today’s Americans are somehow genetically different from their grandparents. But they are now living in one of the most obesogenic environments in human history. They are surrounded by cheap, tasty and highly calorific foods which they are constantly reminded to buy. Something that I think is a large part of the rise in the orange line on this graph, particularly when it comes to snacking.
Fascinatingly, when you dig a little deeper into the data you’ll see that the rise in the average American’s caloric intake is in fact driven by just a few ingredients.
Despite the large rise in total calories the change in energy consumed from vegetables, fruit, meat, dairy and sugar has been very limited. The bulk of the increase has come from flour and oil. And when you drill right down the rise is mostly three ingredients: vegetable oils, wheat flour and corn products.
Together with sugar and salt these three ingredients are the building blocks for a vast array of processed food. Foods that have literally been engineered to create a ‘bliss point‘ that will have you coming back for another endorphin hit.
So although you can lose weight eating almost anything if you control your calories (like a ‘twinkie diet’), eating a lot of calorie dense processed food makes it easy to overeat. When you combine this diet with an increasingly stagnant lifestyle you have a recipe for weight gain.
But what about losing weight? Is it just a matter of eating less processed food, or can we reverse engineer this? Can certain foods actually make it easier to stay in a caloric deficit? I think the answer to this question is such a resounding ‘yes’ that I’ve devoted this whole section to describing ‘filling food’. We’ll look at five filling food groups: lean protein, colourful vegetables, natural fats, watery carbs and juicy fruit.
1: Lean protein
Lean proteins like fish, chicken, beef, low fat dairy and egg whites are the staple foods of body builders for good reason. Not only are they essential for building and maintaining muscle, but they actually make the process of losing fat easier.
There are three clear advantages to eating more lean protein when losing weight. Protein is the most satiating macronutrient, helping to control hunger while in a deficit. Protein helps spare muscle and thus protects metabolic rate to a degree. Lastly protein has a high thermic effect, which basically means around a quarter of the calories in protein are used to process it in the body.
Perhaps the classic example of how this can work for weight loss comes from a 2005 study where 19 people (16 women, 3 men, average weight 160 lbs) where put on a 15% protein maintenance diet for two weeks, followed by a 30% protein maintenance diet for another two weeks and then allowed to eat freely as long as they maintained the 30% protein content.
This resulted in a spontaneous calorie reduction of 440 kcal/day, and over the course of 12 weeks produced an average weight loss of 11 lbs (5 kg) each, most of which was fat. You can see the results below:
Perhaps the most impressive thing about this study was that the satiating effects of higher protein seemed to endure despite falling leptin and rising ghrelin concentrations, hormone changes you would expect to produce a surge in hunger. Which suggests higher protein diets might also help keep weight off too.
So what does a 30% protein diet look like in real life you might ask? In the graph above we are talking about 30% of 2,000 kcal, or roughly 150 grams of protein (very close to 1 g/lbs for the women studied). In the menu shown in the study this was egg whites on toast for breakfast, a turkey breast sandwich for lunch and beef lasagne for dinner. Which brings us nicely to one of the easiest pieces of advice you can follow to lose weight.
Add a decent serve of protein (about the size of your palm) to each of your main meals. This can help keep you full and ensure you lose less muscle by optimizing protein synthesis.
Bottom line: Protein helps keep you full and protects muscle
2: Colourful vegetables
If you were looking for one piece of nutrition advice that everyone in the nutrition world could get behind it would be ‘eat a rainbow of vegetables’.
Among the world’s longest lived people vegetables take the central role in each diet. Regardless of whether they eat relatively low fat (like the Okinawans) or much higher in fat (like Sardinians), a wide range of colourful vegetables are always on hand to provide vitamins, minerals and fibre.
Beyond their obvious role in a healthy diet, vegetables can also be a powerful tool when you are trying to lose weight. Because of their very low caloric density (energy per unit weight) vegetables can be used to add volume to meals. This promotes a stretch reflex in the stomach which reduces Ghrelin levels and sends a fullness signal to the brain.
The idea of eating ‘high volume foods’ has been pioneered by Barbara Rolls, whose Volumetrics Diet builds upon a canon of research showing how the energy density of meals affects how much we eat. The following graph tries to give you a visual summary of how this works, by highlighting the low caloric densities of veggies in terms of calories per gram:
Basically a lot of vegetables are mostly made of water, fibre and micronutrients, meaning they have very low caloric densities. For example 100g grams of celery or cucumber has just 10 calories. A similar amount of salad, tomato and spinach has just 20 calories. Compare this to bread at 260 calories or butter at 700 calories.
Of course knowing this information and using it are very different things. So you need to find ways you can actually enjoy your vegetables, whether that be in soups, smoothies, stews, salads or sandwiches. You simply can’t go wrong piling on veggies with low caloric densities. Be careful to note that due to their starchy nature tubers like potatoes as classified as carbs. So don’t kid yourself that fries are what we’re talking about here!
Bottom line: Veggies add volume, fibre and nutrients to meals
3: Natural fats
When it comes to staying full, fats are the most confusing macronutrient. The traditional view comparing macros is that protein is the most filling, followed by carbohydrates and then energy dense fat the least filling. While this argument can certainly be made for added fat, like the cheap oil in processed foods, tarring all fats with this label is a mistake.
A good supply of fat is essential for hormonal health, aids the absorption of minerals of vitamins and can slow the speed with which your stomach empties. In fact meals including of a sensible amount of healthy fat may actually improve satiety by stimulating production of satiety hormones, in particular PYY.
The easiest way to chose better fats is to focus on ones that naturally occur in foods. Not only do these tend to be more filling, but they are often much healthier too. To give you a clear example of the difference between added and natural fats I’ve grabbed some data from the well known ‘Satiety Index’.
This index tries to compare how filling foods are relative to white bread. I’ve highlighted the high fat foods in white, and you can see that things like eggs and fish do quite well, while the added fat rich croissants, cake and doughnuts aren’t great.
If you are looking for particular fatty foods to add to your diet then it’s hard to go past some classic health foods like fatty fish, avocados, nuts, eggs, seeds, dairy and olive oil. Not only can these add flavour and texture to your diet, but in sensible quantities they can help keep you feeling full, look after your hormonal health and help to reduce inflammation.
Bottom line: Natural fats help keep you full and healthy
4: Watery carbs
When we talk about ‘carbs’ in this section we are mostly interested in ‘starchy carbohydrates’. These are relatively complex carbohydrates like oats, potatoes, rice and pasta that are broken down into glucose and then used for energy in the body. They are the staple foods of endurance athletes with high energy demands, but not actually essential for survival.
Carbs are a fabulous energy source but can be easy to overeat, particularly if they have been processed to remove fibre and water (think breakfast cereal and bread). In order to get your carbs in without blowing your deficit it can often be useful to choose carbs with higher water and fibre content. Think classic bodybuilder foods like oatmeal, sweet potato and brown rice.
Looking at the same satiety index we can see that carbohydrates with higher water and fibre content tend to be more filling.
In this Satiety Index boiled potatoes lead the way, followed by oatmeal and brown pasta. White bread, french fries and cornflakes do less well.
Giving preference to ‘watery carbs’ doesn’t mean you need to shun more processed carbs altogether, but if your goal is to control your hunger while staying in a deficit you could do worse than to focus on carbs high in fibre and water. These will fill you up and give you a more stable energy supply.
The fact that you always see bodybuilders with oatmeal, rice and sweet potatoes on their menus is not a coincidence.
Bottom line: Watery carbs can provide fuel and fullness
5: Juicy fruit
In my experience people often assume that fruit is not useful for weight loss due to its sugar content. While it is true that in very large doses (think soda addiction) fructose can be turned to fat in the liver, what generally happens with a few bits of fruit each day is that they help refill liver glycogen, sending a fullness signal to the brain.
If you’re aiming to stay full in a deficit then the juicier the fruit the better really. Denser fruits like bananas, mango and any dried fruit are easier to overeat, whereas it is very hard to go wrong with juicy fruits like oranges, grapefruit, melon and berries.
In fact switching out some of your starchy carbohydrates for either vegetables or juicy fruit is often a winning strategy for controlling calories. The best example I could find of this in a well controlled study was one comparing Paleo and Mediterranean diets among a group of men with heart disease.
This chart below compares the average daily food weight and energy values of the different diets over the course of 12 weeks. In case you are curious the average weight loss for the 12 weeks was 3.8 kg in the Mediterranean Group and 5.0 kg in the Paleo Group.
Considering neither of these diets strictly controlled for calories their energy content is very low. What this shows us is that a diet based largely on lean meat, fruit and vegetables can be very filling. Particular if you throw in a few further restrictions on things like eggs, nuts, potatoes and oil, as was the case in the Paleo group here.
If you look at the food weights above you’ll see the Paleo group were putting away over half a kilo of fruit per day. Clearly, by swapping out dairy and cereals for more fruit and vegetables the Paleo group managed to lower calories while keeping the volume of food they were eating up. A useful reminder that juicy fruits can be a valuable tool for weight loss.
Bottom line: Juicy fruits are convenient fat loss foods
The Filling Food Plate
Now obviously at this point I’ve dropped a lot of information on you, making it hard to use. So what I thought I’d do was stick the whole lot on a plate, giving you a decent template for what a filling plate of food might look like.
Now just to be clear, this is only a template. You can make a very filling plate of food that looks nothing like this, and in many ways this format works better for lunch and dinner than it does for breakfast.
It’s a pretty simple idea, just grab some food from each group. A palm worth of protein, a few handfuls of veggies, a thumb or two of natural fat for flavour, a fist size of watery carbs for energy, and chase it down with a serve of fruit to finish.
Don’t get too literal with the spacing. You can make this work for Italian or Thai just as easily as it will for meat and three veg. It is just a way to combine our filling foods onto one plate of food, because at the end of the day most of us eat meals rather than foods.
The arrows provide a hint that if you go high in fat you’ll want to tone down the carbs, or high in carbs means less fat. This is just because they are major calorie sources, so if you want to ramp up one the other has to give. Veggies and juicy fruit exchange well as they both have low caloric densities. So switching from green veg to berries isn’t such an issue.
If you have any experience with calorie or macro counting you’ll quickly see that as a visual guide this is a handy way to ballpark a decent portion size on the run without obsessing about the numbers.
Bottom line: The filling food plate is a template for portion control
The best diet is . . .
At this point I’m duty bound to point out that ‘filling foods’ are simply a tool for losing weight. When used well they can help you stay full during a deficit and ensure you get a nice balance of macro and micronutrients. But as with all things in nutrition they can also be taken too a point where people get obsessed with ‘clean’ or ‘healthy’ foods in a way that does more harm than good.
Your weight loss results will depend in large part on the number of calories you put in your mouth. Eating mostly whole foods normally makes controlling calories easier, but you’ve also got to enjoy what you eat and be flexible enough to fit this around your social life. So don’t be afraid to make room for some ‘junk’.
You see the harsh reality of diets is that all of them work . . . until they don’t. This is often around the six month phase when people lose the will to stick with restrictive rules as they are confronted with stalling results.
Just look at the data from this meta study comparing the results of 8,000 people using different diets to lose weight.
If you really squint hard enough at this chart you might conclude that low carbohydrate approaches seem to result in more weight loss at six months, while low fat diets do better at twelve months. But to be honest this is splitting hairs.
What this graphs says to me is that all diets generally work for six months, but by twelve months many people are already gaining that weight back. This is in fact so common it has become a virtual rule among obesity researchers.
Which brings me nicely to some final words of wisdom I hear occasionally in the fitness industry:
The best diet is the one you can stick to
At the end of the day you’ve got to enjoy what you eat. If the approach you are using is based primarily on foods that you hate, you’ve got a serious problem. The solution is to get smart about your food choices so you are able to adapt your diet in a way that works for you and your life.
Personally I find the balance between nutritious whole foods and calorie dense junk fits well into a classic 80/20 framework. That is, if 80% of my calories are coming from nutrient rich whole foods I can squeeze in 20% from ice cream or chocolate purely for taste. This might be one treat per day, or banked into a weekly social splurge. Of course this very much depends on personality, as some people do better abstaining than moderating.
Bottom line: You need to like the food in order to stick to a diet
Eating filling foods makes maintaining a caloric deficit easier. Five food groups that can help keep you in a deficit are lean protein, colourful vegetables, natural fats, watery carbs and juicy fruit. You don’t need to eat these foods all the time, but they should probably be the bulk of your diet.
Next up will ask how many calories to lose weight.