You’ve decided to change the way you eat and improve your health. You are determined to clean out your pantry and refrigerator, go to the supermarket and stock up on health food.

Don't bother. Think smaller.

People who make tiny changes to their diet over time — and stick to them — tend to end up healthier than those who make no changes or pursue drastic changes they eventually find too difficult to maintain. This is what researchers at the Harvard Chan School of Public Health found when they looked at the diet quality of nearly 74,000 adults over a 12-year period and then at their risk of dying over the next 12-year period.

The participants were part of the Nurses’ Health Study and the Health Professionals’ Follow-up Study. Using three measures of diet, the researchers scored different foods or nutrients in people's diets, with the healthiest getting higher scores. Lower scores were assigned to less healthy foods and nutrients.

Those people who made small improvements in diet quality over the first 12 years of the study had a lower risk of death in the second 12 years than people whose diets remained the same, regardless of which method of diet scoring was used. It will come as no surprise that the food groups that contributed most to a better diet were whole grains, fruits and vegetables, along with fish and omega-3 fatty acids.

You don’t have to make radical, overnight changes to your diet in order to improve your health. In fact, the opposite may be true.

The sorts of sustainable changes that made the biggest difference in reducing the risk of premature death were things like substituting a serving of nuts or legumes for a serving of red or processed meat, or drinking water instead of sugary beverages on a daily basis. Changes like these increased diet quality scores and lowered the risk of death by 8 to 17 percent, depending on diet score. However, when diet scores decreased — when diets became even less healthy — there was a 6 to 12 percent increase in the risk of death.

People who maintained higher diet scores for 12 years were 9 to 14 percent less likely to die. Those who began the study with unhealthy diets and improved their diet scores the most also had a significantly smaller risk of death in the following 12 years.

“Our results highlight the long-term health benefits of improving diet quality with an emphasis on overall dietary patterns rather than on individual foods or nutrients. A healthy eating pattern can be adopted according to individuals' food and cultural preferences and health conditions. There is no one-size-fits-all diet,” said Frank Hu, senior author of the study and professor and chair of the Harvard Chan School Department of Nutrition, in a statement.

The lesson here is that you don’t have to make radical, overnight changes to your diet in order to improve your health. In fact, the opposite may be true. Small changes over time add up to a better diet that you’re more likely to stick with.

Focus on an overall healthy eating pattern rather than eating more or less of any one nutrient like protein, carbohydrates or fats. Find a healthy eating pattern you can live with because that is the most successful diet of all.

The study is published in the New England Journal of Medicine.