Most diets fail because of unsustainability. This is often because of particular food restriction or restrictions on entire food groups. In an instance where an individual doesn’t follow every rule laid out by a fad diet, they have no idea how to adjust the rest of their diet to accommodate the earlier muck up, and this can lead to a chain of binge/purge cycles. For example: worrying that the small bowl of ice cream you ate will completely stop your chances of weight loss for the day so you might as well go all out and eat the whole tub. This type of black and white thinking about nutrition can impede people’s ability to maintain a healthy weight once achieved (1).
To give you a bit of background, flexible dieting AKA IIFYM (if it fits your macros) is a dietary strategy which has a main focus on reaching target macronutrient and calorie numbers by the end of the day. It does not directly discriminate between “good” and “bad” foods or “clean” and “unclean”. To do so is missing the bigger picture. These macronutrient and calorie targets are often set through trial and error as to how training performance and body weight/composition responds. If planned with health in mind, a dietary fibre target will also be present. Reaching a daily fibre target of around 25-40g/day (depending on caloric intake) will aid in gastrointestinal system health and help blood sugar levels stay relatively stable. It will also indirectly ensure that you are consuming a large amount of some of the micronutrients.. as most foods that are high in fibre are also high in micronutrients.
One huge misconception that people have about flexible dieting is that it gives you permission to eat junk food all day so long as it “fits the macros”. There is something inherently wrong with that idea. Suitable macros ESPECIALLY when someone is trying to lose a great deal of body fat, like during bodybuilding contest prep, will not allow a large intake of calorie dense, unfilling, “unhealthy” foods. For example, if you are eating 2000 calories per day of about 150g protein, 250g carbs, 50 fat, and 30 fibre, you simply won’t have enough room in your macro quota to fill it with pure junk. You would end up not reaching the protein or fibre target.
Thus, flexible dieting often involves eating a decent amount of typical “bodybuilder” foods like chicken and broccoli, just because these foods are of low caloric density and make you full for the amount of calories that they have in them. When you are on 3000-4000 calories however, there becomes a lot of room to fit in a wider range and quantities of foods you desire, just be sure to still hit the calorie, protein, and fibre quota for the day, eat some fruits and vegetables, and your health will be just fine. Remember, look at your diet and lifestyle as a whole to determine whether it is healthy or not, rather than nit-picking at smaller details in your diet like if you should put a teaspoon of sugar in your coffee or not.
Where it trumps other styles of diets is the flexibility that it has. It means you don’t have to be a social outcast and bring tupperware out to lunch with your friends. Not to hate against anyone who does that, just saying that it is unnecessary suffering. You can eat what you like when you go out, as long as you have a decent estimate of the macronutrient profile of the meal. Once you have used flexible dieting for an extended period of time, you will have a greater understanding for the nutrient profile of select foods, and will be able to eat intuitively without having to track calories/macros. That is the end goal.
In the next article I will provide a case study on a bodybuilder transitioning from deep in the off season, to late in contest prep, as an example of how a flexible diet changes when calorie and macronutrient targets change. Stay tuned!
- (1) Palascha, A., van Kleef, E., & van Trijp, H. C. (2015). How does thinking in Black and White terms relate to eating behavior and weight regain?. Journal of health psychology, 20(5), 638-648.