How to Choose a Diet That'll Actually Work for You

The short version

• Large trials keep finding that popular diets produce similar weight loss when calories are comparable.
• How long you stick with a diet predicts your results better than which diet you chose.
• Pick by asking what you can live with, what your health needs, and what you can afford.
• Try one for four to eight weeks. If you hate it, switching isn't failing.

What the research keeps finding

These studies are worth knowing because they change how you think about the whole question:

• DIETFITS (2018). 609 adults were assigned to healthy low-fat or healthy low-carb diets for a year. Average loss was about 11 to 13 pounds on both, with no significant difference. Testing people's genes and insulin levels didn't predict who'd do better on which diet.
• POUNDS LOST (2009). 811 adults on diets with very different mixes of fat, protein and carbs lost about the same amount at two years.
• Atkins, Ornish, Weight Watchers and Zone (2005). Weight loss was similar across all four. People's self-reported adherence was the thing that mattered, whichever diet they were on.
• A review of 14 named diets (2020). Most led to modest weight loss at six months, and much of the benefit had faded by a year.

The averages hide big individual differences. In DIETFITS, some people lost 60 pounds while others gained 20. So there probably is a best diet for you, but no one can pick it from a list. You'll have to find it by trying.

Six questions to narrow it down

1. What do you refuse to give up? If you can't imagine life without bread, skip keto. If you love steak, veganism will be a struggle.
2. Do you like rules or hate them? Some people find clear rules (no eating after 7 p.m.) easier. Others rebel immediately.
3. Do you want to count? If numbers help you, try calorie counting. If they make you miserable, choose a no-count style.
4. What's your health situation? Your conditions may narrow the list. See the table below.
5. Who else is at your table? Cooking separate meals for your family gets old fast.
6. What fits your budget and schedule? A plan that needs two hours of cooking won't survive a busy week.

If this sounds like you, try this

How to try one

• Commit to four to eight weeks. Long enough to get past the awkward start.
• Track a couple of things. Your weekly average weight and how you feel.
• Ask a simple question at the end. Could I see myself eating this way in a year, at least mostly? If not, change it.

Switching isn't quitting. It's how you find what works.

Ready to look at them side by side? Compare all the diets.

Sources

1. Gardner et al., JAMA (2018): Low-fat vs low-carb diet (DIETFITS)
2. Sacks et al., NEJM (2009): Comparison of weight-loss diets with different compositions
3. Dansinger et al., JAMA (2005): Atkins, Ornish, Weight Watchers and Zone compared
4. Ge et al., BMJ (2020): 14 popular named diets compared

This guide is general information, not medical advice. Please check with a clinician before making big changes, especially if you have a health condition, take medication, or are pregnant. Read the full disclaimer.