Calorie Intake for Weight Loss

Question
I am trying to lose weight while training for triathlons.  I currently weigh 160
and am 5'8 with a BMI of 27.8.  I work out 5-6 days a week doing cycling,
swimming, running, or a combo of them.  How many calories should I be eating
to lose weight?  I have tried 1800-1900 from a trainer suggestion for 2 weeks
and haven't lost a pound.  I haven't gained any..I am just stuck.

Answer
Great question, and congratulations on your goals of triathlons - that is inspiring!

In answer to your question, almost everyone will lose weight with a diet of 1800-1900 kcal per day intake, especially with significant sustained exercise as you are describing.  Even if you have an unusually low basal metabolic rate, an hour a day of exercise will usually consume well over 500 additional kcals.  You are probably burning over 2200 kcals per day now total, so you are in a great position, if you can sustain an 1800kcal per day diet, to win over time: both in losing weight, and in becoming fitter and healthier.

It is a slow process, however.  It might take 1-2 weeks to lose a single pound.  And studies show we all underestimate our calorie intake.  Another interesting fact that studies have shown is that we tend to eat more after we have worked out hard, partly because we let ourselves loosen up our own dietary restrictions.  So guard against those potential lapses that might cost you a few hundred calories.

So, my advice is to keep sharp daily focus on your goals.  Eat protein at breakfast every morning, don't skip breakfast, continue your workouts, set a date for your first triathlon and compete even if you do not like the weight you're competing at, and never give up.  It can take a long time to show results, but even with a very modest 250 daily kcal deficit, you would lose 26 pounds in 12 months.  You can do it.  I think you have already taken several major steps toward accomplishing your goals.

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