Does cutting a 100 calories here and there really help?

Yes and no, but mainly no.

Yes in that it can get you moving toward your goal. But no, it won’t help you lose significant weight.

Numerous scientific studies show that small caloric changes have almost no long-term effect on weight. When we skip a cookie or exercise a little more, the body’s biological and behavioral adaptations kick in, significantly reducing the caloric benefits of our effort.

As a recent commentary in The Journal of the American Medical Association noted, the “small changes” theory fails to take the body’s adaptive mechanisms into account. The rise in children’s obesity over the past few decades can’t be explained by an extra 100-calorie soda each day, or fewer physical education classes. Skipping a cookie or walking to school would barely make a dent in a calorie imbalance that goes “far beyond the ability of most individuals to address on a personal level,” the authors wrote — on the order of walking 5 to 10 miles a day for 10 years.

As a trainer, this is significant scientific research that everyone must be aware of.  I often see clients who want to lose, say 25 pounds.  It is not done by just skipping dessert or switching from regular Coke to Diet Coke. It is done by knowing how may calories you eat every day and reducing that amount significantly (e.g. 15% to 30%, depending on the person).  Don’t get lured into thinking that “eating healthy” is the same as reducing calories.

Dr James O. Hill, director of the Center for Human Nutrition at the University of Colorado Denver, says that while weight loss requires significant lifestyle changes, taking away extra calories through small steps can help slow and prevent weight gain.

“Once you’re trying for weight loss, you’re out of the small-change realm,” Dr Hill said. “But the small-steps approach can stop weight gain.”

I highly recommend reading the full article here.