What is flexible dieting?Nutrition
Flexible dieting is like a budget
Some people think that flexible dieting means you can eat whatever you want, as long as you hit your macros. And while you could, in theory, hit your macros eating highly processed “junk” foods, that doesn’t imply that you should.
Rather, think of flexible dieting as a budget.
Just because you have money doesn’t mean you’d spend it on sports cars, boats, or other luxuries - especially if you have bills and rent to pay.
And just because you have calories doesn’t mean you should spend them all on cookies, bars, and cheesecake - especially if that leaves your micronutrient and fiber needs unmet.
Where your calories and macros come from matters: your food choices can make or break your diet and health in the long-term.
In this article, we’ll discuss why - and how you can best budget calories to reach your fitness goals.
Treat your calories like your finances
When you’re considering buying a new car, you likely ask yourself a variety of questions…
- Do I have enough money to afford it?
- What are the benefits of buying this car?
- Can I buy it and still have enough money to pay my bills?
- Are there better ways I can use this money?
- Would I really enjoy and use this car? Or is there another car I’d like better?
You probably wouldn’t buy the car if it made it hard to pay rent or afford other more important items (i.e., food, a gym membership, or your daughter’s Christmas gift). And you probably wouldn’t buy the car if you didn’t really want it, or if there was a cheaper option that also fit your preferences.
Your food choices are no different.
When you consider eating a particular food, you should ask yourself…
- Does this food fit within my calorie target?
- What macronutrients does this food provide?
- Can I eat this food and still hit my protein, fiber, and micronutrient needs?
- Am I going to be hungry later if I spend most of my calories on this food?
- Does this food upset my stomach?
- Do I actually enjoy and want this food? Or is there another food I’d like better?
If eating a huge slice of cheesecake consumes most of your daily calories - so you can’t reach your protein or fiber goals and feel hungry the rest of the day - maybe you should opt for another food.
But maybe you have a high-calorie budget, so you can eat cheesecake while hitting your macros and warding off hunger. In which case, there’s nothing wrong with enjoying a slice.
Context matters: the higher your calorie budget, the more room you have for calorie-dense foods.
So although a calorie is a calorie, food provides more than just calories. And food is more than just macros. Let’s dive into why.
Why food is more than just macros
Your total calorie and macro intake ultimately determines whether you lose, gain, or maintain weight. However, for overall health, energy, and longevity, you should also consider your micronutrients, fiber, and saturated fat intake. And when it comes to long-term dietary adherence, you can select more or less satiating foods to help you more easily hit your macros.
Micronutrients (i.e., vitamins and minerals) contain no calories but support a variety of physiological processes, from blood clotting to energy metabolism. Micronutrient deficiencies can have widespread effects on health and contribute to acute and chronic diseases. Moreover, getting adequate amounts of essential micronutrients may help regulate appetite to prevent overeating(1).
Overall, food processing can reduce micronutrient content of fruits, veggies, and meats - especially when heat is applied during procedures like canning(2). And processing can also inactivate or destroy naturally occurring enzymes that aid in digestion and nutrient absorption.
Then there’s ultra-processed foods - like chips, candy, and soda - which contain little-to-no whole food ingredients. As you might expect, research has found that diets high in ultra-processed foods contain lower levels of micronutrients(3, 4), such as..
- Vitamins A, C, D, E, B12
So, it’s safe to assume that the more processed a food is, the lower its micronutrient content.
While fiber isn’t considered an essential nutrient, consuming fiber is important for both gut and heart health, preventing diseases such as type 2 diabetes, cardiovascular disease, and colorectal cancer. Dietary fiber intake has even been associated with reduced risk of all-cause mortality(5)!
Beyond these benefits, eating enough fiber can support sustainable weight loss by curbing hunger. Specifically, dietary fiber slows gastric emptying and stabilizes blood sugar levels, which enhances satiety to prevent overeating. In addition, many fiber sources tend to be less energy dense, so you can eat more volume per calorie.
The USDA currently recommends 14 grams of fiber for every 1000 calories consumed: about 25-30 grams daily on a ~2000 calorie diet and 35-40 grams daily on a ~2500 calorie diet.
Good sources of fiber include…
- Beans and legumes
- Whole fruits (with the skin)
- Whole grains
- Nuts and seeds
Saturated fat is found in animal products (i.e. meat, eggs, dairy) and coconut oil - and is particularly high in many processed foods. Because excessive saturated fat intake may impair heart health (6), eating no more than 10% of your total daily calories from saturated fat is generally recommended. So swap some of your saturated fat with more “heart healthy” polyunsaturated or monounsaturated fats to reduce the risk of cardiovascular disease(7, 8, 9).
Satiety Factors: Calorie Density & Palatability
Depending on your calorie budget, you may find yourself struggling with feelings of hunger (in a deficit) or excessive fullness (in a surplus). In this case, you may also want to choose more or less satiating foods.
…But what exactly makes food “satiating?”
Holt and colleagues helped answer this question through research validating a “satiety index” that ranks foods based on subjective satiety ratings(10). In doing so, they identified several key factors contributing to satiety.
Specifically, they observed that more satiating foods tend to be…
- Higher in protein
- Lower in fat
- Higher in fiber
- Higher in water content
- Lower in palatability
In simpler terms, more filling foods are less calorie dense and less palatable. Less calorie-dense foods provide more volume per calorie, which can enhance satiety through gastrointestinal mechanisms, such as stretch receptors in your stomach(11). And less palatable food facilitates appetite regulation - which often goes awry with hyperpalatable foods high in sugar and fat(12, 13, 14).
Whole foods > junk food
While all that might be slightly hard to digest (ha!), you can hit most of these recommendations simply by prioritizing less processed or “whole” foods. Getting ~80% of your diet from minimally processed meats, dairy, fruits, veggies, and whole grains makes it much easier to hit your micronutrient needs and fiber targets while keeping your appetite in check. If your calorie intake is relatively low, like during a deficit, this rule-of-thumb becomes even more crucial.
How to best budget your calories
With these guidelines in mind, you can strategically budget your calories to more easily attain and sustain your fitness goals. Whereas a lower calorie budget favors food choices that maximize satiety and micronutrition, a higher calorie budget leaves room for more palatable and calorie-dense foods.
Eating with a low-calorie budget
When you have a low-calorie budget, it can be hard to cut calories without suffering hunger and cravings. In addition, with lower calories you need to be more conscientious about micronutrition - and choose “high-quality,” nutrient-dense foods to maintain optimal health.
That is, overall, your diet should primarily include foods that are…
- Less calorie dense.
- More micronutrient dense.
And while that doesn’t mean you can’t have more palatable, calorie-dense foods, eating a 900-calorie slice of cheesecake can make it hard to satisfy your macros, micros, and appetite with a 1500-calorie budget.
Eating with a high-calorie budget
When you have a high-calorie budget, you can afford to eat more “fun” foods and might even need such foods if your appetite is lacking. In particular, you can incorporate foods that are more calorically dense and palatable.
For example, if you’re struggling to eat enough, you can…
- Add oil to veggies and salads.
- Use nut and seed butters.
- Drink some of your calories (i.e., use milk, juice, smoothies, and shakes)
- Sprinkle nuts and seeds atop salads, yogurt, ice cream, or oatmeal.
- Add generous amounts of oil to grease pots and pans for cooking.
- Eat a wider variety of foods(15).
- Enjoy some more processed treats.
If you have a 3500-calorie budget, you can more easily fit in a 900-calorie slice of cheesecake and have sufficient calories left to hit your macros, micros, and fiber intake. In fact, you might find it nearly impossible to eat 3500 calories entirely from whole foods and plants due to their high satiety index.
Flexible dieting trade-offs
Flexible dieting gives you the freedom to choose any food: no food is eliminated, off-limits, or “bad.”
Nonetheless, some foods better support your fitness and health goals than others. And certain food choices can make meeting your calories and macros easier or harder.
Every dietary decision has a trade-off, as with any budget. By consuming calories from “junk” food you’re missing out on micronutrients and fiber from fruits and veggies. Junk food isn’t inherently bad - but if it interferes with you hitting your macros, micros, and fiber, you may need to reconsider your food selection.
Just because you have a budget doesn’t mean you can spend it however you want. And just because you can eat anything doesn’t mean you necessarily should.
With the freedom of flexible dieting comes the responsibility of making decisions that best align with your goals.
So consider whether eating that cheesecake is really worth it to you. Can you enjoy it within your calorie budget while getting enough nutrients from other foods? Or will it make the rest of your day’s meals a challenge?
The choice is ultimately up to you.
- Tremblay, A., & Bellisle, F. (2015). Nutrients, satiety, and control of energy intake. Applied Physiology, Nutrition, and Metabolism, 40(10), 971-979.
- Prochaska, L. J., Nguyen, X. T., Donat, N., & Piekutowski, W. V. (2000). Effects of food processing on the thermodynamic and nutritive value of foods: literature and database survey. Medical Hypotheses, 54(2), 254-262.
- Martini, D., Godos, J., Bonaccio, M., Vitaglione, P., & Grosso, G. (2021). Ultra-processed foods and nutritional dietary profile: a meta-analysis of nationally representative samples. Nutrients, 13(10), 3390.
- Micek, A., Godos, J., & Grosso, G. (2021). Nutrient and energy contribution of ultra-processed foods in the diet of nations: a meta-analysis. European Journal of Public Health, 31(Supplement_3), ckab164-418.
- Park, Y., Subar, A. F., Hollenbeck, A., & Schatzkin, A. (2011). Dietary fiber intake and mortality in the NIH-AARP diet and health study. Archives of internal medicine, 171(12), 1061-1068.
- Hooper, L., Martin, N., Jimoh, O. F., Kirk, C., Foster, E., & Abdelhamid, A. S. (2020). Reduction in saturated fat intake for cardiovascular disease. The Cochrane database of systematic reviews, 5(5), CD011737. https://doi.org/10.1002/14651858.CD011737.pub2
- Mozaffarian, D., Micha, R., & Wallace, S. (2010). Effects on coronary heart disease of increasing polyunsaturated fat in place of saturated fat: a systematic review and meta-analysis of randomized controlled trials. PLoS medicine, 7(3), e1000252.
- Kim, Y., Je, Y., & Giovannucci, E. L. (2021). Association between dietary fat intake and mortality from all-causes, cardiovascular disease, and cancer: A systematic review and meta-analysis of prospective cohort studies. Clinical Nutrition, 40(3), 1060-1070.
- Gillingham, L. G., Harris-Janz, S., & Jones, P. J. (2011). Dietary monounsaturated fatty acids are protective against metabolic syndrome and cardiovascular disease risk factors. Lipids, 46(3), 209–228. https://doi.org/10.1007/s11745-010-3524-y
- Holt, S. H., Brand Miller, J. C., Petocz, P., & Farmakalidis, E. (1995). A satiety index of common foods. European journal of clinical nutrition, 49(9), 675-690.
- Ritter, R. C. (2004). Gastrointestinal mechanisms of satiation for food. Physiology & behavior, 81(2), 249-273.
- de Macedo, I. C., de Freitas, J. S., & da Silva Torres, I. L. (2016). The influence of palatable diets in reward system activation: a mini review. Advances in pharmacological sciences, 2016.
- Erlanson‐Albertsson, C. (2005). How palatable food disrupts appetite regulation. Basic & clinical pharmacology & toxicology, 97(2), 61-73.
- Markus, C. R., Rogers, P. J., Brouns, F., & Schepers, R. (2017). Eating dependence and weight gain; no human evidence for a 'sugar-addiction' model of overweight. Appetite, 114, 64–72. https://doi.org/10.1016/j.appet.2017.03.024
- Rolls, B. J., Rolls, E. T., Rowe, E. A., & Sweeney, K. (1981). Sensory specific satiety in man. Physiology & behavior, 27(1), 137-142.