What the Best Diets Have in Common
Fat loss ultimately comes down to calories in vs. calories out. The best diets, in one way or another, involve eating less.
You can't lose fat without being in an energy deficit: consuming fewer calories so your body has to use some of those stored calories around your waist. Alternatively, if you're constantly eating at an energy surplus, those extra calories will be stored as body fat, making you squishier and unhealthier.
While the core principle is simple, the execution is difficult. That's a big part of why we have an obesity epidemic. To fix this on an individual level, you need to adjust your eating habits in a way where you take in fewer calories.
One of the biggest culprits behind preventing this? Food variety. I'd argue that food variety is one of the biggest reasons people are accumulating fat tissue faster than a Kardashian accumulates divorces.
So why is food variety a problem? And what can you do about it?
Fullness or satiety isn't primarily determined by your stomach but rather your brain. The fullness level of your stomach is just one of many signals that tells your brain to advise you to stop eating. To reduce caloric intake, you need to tell your brain to "get full" sooner.
Your brain sends the "full" signal faster if you're eating the same food. This is called sensory-specific satiety (1-5). The pleasantness of a food declines after a while, especially if that food is simple in taste and texture. So, satiation isn't necessarily when you get full on food, but when you get full of a flavor. You're essentially reaching taste fatigue.
This is where food variety can become a problem. Each time you introduce more flavors or textures, your appetite sort of resets. Eat some plain potatoes and that'll get boring, but introduce some sour cream and, suddenly, you can eat more. Add in a side of macaroni and pair it with some alcohol. Your appetite suddenly expands to new limits.
This is why you always have room for dessert. You could eat yourself silly and feel like your belt is going to explode, but if a tantalizing dessert is presented, appetite magically reappears.
Most human and animal research finds that food variety drives caloric intake (6). You'll naturally eat more when more variety is available within or after a meal.
For example, subjects unknowingly ate 33% more calories when offered sandwiches with four fillings compared to one filling (8). In the same study, subjects also consumed more calories when a variety of yogurts were available.
Another study gives us even further perspective (9). It split subjects into six groups:
- One group had French fries with no ketchup. (Monotonous group.)
- One group had French fries with ketchup available. (Simultaneous group.)
- One group was first served plain French fries, then ketchup was made available. (Successive group.)
- One group had brownies with no toppings. (Monotonous group.)
- One group had brownies with ice cream and whip cream available. (Simultaneous group.)
- One group was first served plain brownies, then ice cream and whip cream were made available. (Successive group.)
The simultaneous groups ate 25% more calories. You can obviously eat more fries if you get some ketchup (savory and sweet flavors). The same goes for brownies with ice cream and whip cream (new textures and flavors).
However, the successive groups ate 40% more calories when forced to eat the treats alone before introducing sauces and toppings. They were probably satisfied until the new flavors and textures showed up.
Imagine how much more the average person eats when eating a multicourse meal where endless flavors arrive one after the other. And let's not even talk about buffets. The caloric intake can be astronomical.
This is why diets like keto aren't magical. They merely limit your choices, so food variety is reduced. That drives caloric intake down and further reduces your chances of eating high-calorie foods.
Even a health-conscious person trying to lose body fat struggles with variety. They think having tons of fancy ingredients will turbo-charge their health, but their caloric intake is still too high.
Their breakfast is a fancy, multi-ingredient concoction of avocado toast and acai bowls. Their "healthy" salad for lunch has different nuts, seeds, avocado, cheese, croutons, toppings, and dressings. By dinnertime, they're already in a caloric surplus for the day.
No, you don't have to eat plain chicken breasts and broccoli at every meal. But if you're struggling to lose fat, it's better to cut down your food variety and have simpler meals, at least until you reach your fat loss goals.
Yes, this makes your life more boring for a while, but that's often the trade-off required. Eating similar foods daily is pretty much what all successful dieters do. Research shows this is a highly effective way to reduce caloric intake without tracking calories, even for people who've struggled with weight loss for years (10). Without endless variety, they simply feel full faster.
Simplifying your meals also saves time and reduces the guesswork involved with nutrition. When it comes to eating for fat loss, less is more and simple is sexy. If you're getting bored, it's probably working.
- Rolls RJ et al. Sensory Specific Satiety in Man. Physiol Behav. 1981 Jul;27(1):137-42.
- Yang X et al. Secondary Rewards Acquire Enhanced Incentive Motivation via Increasing Anticipatory Activity of the Lateral Orbitofrontal Cortex. Brain Struct Funct. 2021 Sep;226(7):2339-2355.
- Havermans RC et al. Food Liking, Food Wanting, and Sensory-Specific Satiety. Appetite. 2009 Feb;52(1):222-225.
- Hetherington M. et al. Sensory-Specific Satiation and Satiety. Satiation, Satiety and the Control of Food Intake, Woodhead Publishing, 27 Mar. 2014.
- Embling Ret al. Effect of Food Variety on Intake of a Meal: A Systematic Review and Meta-Analysis. Am J Clin Nutr. 2021 Mar 11;113(3):716-741.
- McCrory MA et al. Dietary (Sensory) Variety and Energy Balance. Physiol Behav. 2012 Nov 5;107(4):576-83.
- Rolls BJ et al. Variety in a Meal Enhances Food Intake in Man. Physiology & Behavior, Elsevier, 19 Mar. 2003.
- Brondel L et al. Variety Enhances Food Intake in Humans: Role of Sensory-Specific Satiety. Physiology & Behavior, Elsevier, 1 Feb. 2009.
- Epstein LH et al. Long-Term Habituation to Food in Obese and Nonobese Women.Am J Clin Nutr. 2011 Aug;94(2):371-6.