I repeatedly hear clients say they’re going to try “X” diet again because it worked for them the last time. Let’s take a second to analyze this sentence. The key words in this sentence are “again” and “worked.” If you need to do it “again,” then it didn’t “work!” A diet should be a lifelong way of eating, not a short-term plan to fix months or years of poor choices. So what does the perfect diet entail?
The perfect diet varies from person to person. Much like exercise goals determine exercise prescription, your health and/or fitness goals determine what diet is best for you. While elite athletes and individuals with diseases may have strict guidelines to follow, the general population doesn’t, regardless of the latest celebrity diet. Follow these simple rules and you’ll have success!
1. Calories are KEY!
There’s no way around the law of thermodynamics. If you want to lose weight, you MUST be in a deficit. If you want to gain weight, you MUST be in a surplus. If you want to maintain weight, you MUST be at balance.
2. Essential Macronutrients
Essential macronutrients are well, essential. Seems like common sense, right? I thought so too, but a huge section of the industry and general public still love to demonize fat, carbs or protein. They all are essential and should never be eliminated or severely restricted.
3. Variety/balance
A large variety of nutrient-dense food is critical to meet all vitamin and mineral requirements. If you struggle getting in a large variety of high-quality nutrient-dense foods, a multivitamin and mineral complex may be a good idea.
4. Sustainability
It has to be sustainable. The problem with many “diets” is that they’re hard to sustain. They’re too extreme in some ways and lead to broken willpower and binging/weight regain. As we know, yo-yo dieting is bad for long-term weight management.
Reality
Pretty boring, right? Not what you expected? Think you were going to get something a little more profound and definitive? Something with must-eats and must-not-eats? Many nutrition and fitness gurus would like you to believe that, but it’s simply not true.
Click graphs to enlarge! 
Take Home Message
A diet is a lifelong way of eating, not a short-term solution, for any health or fitness goal. Determine what you can sustain long term and include all essential macro- and micronutrients (vitamins and minerals). In general, lean protein and high-fiber carbohydrates, fruits, and vegetables should comprise most of your caloric intake. However, don’t hesitate to eat things you enjoy as long as you are getting in everything else you need! Nutrition is simple, don’t over complicate it.