According to a study published in November 2015 in the journal Nature, a diet high in carbohydrates — like added sugar, white bread, cookies, and cakes — reduces HDL cholesterol levels, increasing the risk for metabolic disorders. Refined carbohydrates found in foods labeled “low-fat” make these just as bad as full-fat foods because the fat is often replaced with carbohydrates from added sugar and other starches.
HDL is plasma’s smallest and densest lipoprotein. The major apolipoproteins of HDL are apo A-I and apo A-II, the alpha lipoproteins. An elevated concentration of apo A-I and apo A-II, known as hyperalphalipoproteinemia (HALP), is associated with a lower risk of CHD. Conversely, hypoalphalipoproteinemia increases the chances of CHD development.  HALP generally does not produce any unusual clinical features (although corneal opacity has been associated with the condition), and it should not be considered a disease entity but rather a fortuitous condition that can increase longevity because of the related decrease in CHD incidence. 
Total cholesterol is a measure of the total amount of cholesterol in your blood, which includes HDL, LDL and triglycerides. However, total cholesterol is mainly made up of LDL or “bad” cholesterol. Having high levels of low-density lipoprotein or LDL can lead to plaque buildup in your arteries, increasing your likelihood for heart disease and stroke. LDL also raises your risk for a condition called peripheral artery disease, which can develop when plaque buildup narrows an artery supplying blood to the legs. The good news is that the higher your HDL level, the lower your body’s LDL level or “bad” cholesterol.
Foods naturally rich in soluble fiber have proven particularly good at lowering cholesterol. Excellent sources include oats, oat bran, barley, peas, yams, sweet potatoes and other potatoes, as well as legumes or beans, such as pinto beans, black beans, garbanzo beans, and peas. Vegetables rich in soluble fiber include carrots, Brussels sprouts, beets, okra, and eggplant. Good fruit sources are berries, passion fruit, oranges, pears, apricots, nectarines, and apples.
Besides putting your heart health at risk, sugar is also known to be one of the most significant contributors to metabolic syndrome. In fact, the recent 2015 Dietary Guidelines labeled sugar as a “nutrient of concern” and voiced recommendations for added sugars to not exceed greater than 10% of total daily calories. So, if your goal is to nip sugar in the bud and increase your HDL cholesterol levels, start by evaluating your libations.
Typically, a fasting plasma lipid profile is ordered to measure LDL, HDL, total cholesterol, and triglyceride levels. Lipids in plasma and in isolated lipoprotein fractions are quantified by enzymatic methods. Prior consumption of food has little effect on the determination of HDL, with postprandial blood samples usually yielding results that can be well interpreted. [14, 2] Current clinically available techniques can determine the cholesterol content, but not the biologic function, of HDL particles. 
Large doses of vitamin B3, or niacin, have been found to raise HDL as much as 20 percent and are often prescribed for people with cholesterol problems. But keep in mind that a daily multivitamin contains all the niacin most people need. Supplementing beyond that can have a variety of side effects, including facial flushing, heartburn and even liver damage, so don’t try it without consulting a doctor.
To maintain a healthy body, you should exercise on a daily basis. If you want another specific reason to start exercising or increase your frequency of exercise, it’s your HDL levels. Increased physical activity directly helps raise your HDL cholesterol — just another one of the many benefits of exercise. Vigorous exercise is the best choice for boosting HDL, but any additional exercise is better than none. (2)
Garlic packs a serious health punch. Some people love the flavor and others have been using it as a kitchen cure to boost immunity and promote heart health for years. Recent research has backed garlic's health benefits, especially for your heart. Garlic, along with garlic extract, has been shown to lower cholesterol, possibly by preventing cholesterol from being made in the liver. Plus, eating garlic may also help lower blood pressure. Give your heart a boost and add garlic to your sauces, salad dressings and stir-fries.
Saturated fats. Typical sources of saturated fat include animal products, such as red meat, whole-fat dairy products, and eggs, and also a few vegetable oils, such as palm oil, coconut oil, and cocoa butter. Saturated fat can increase your levels of "bad" LDL cholesterol. But it has some benefits, too — it lowers triglycerides and nudges up levels of "good" HDL cholesterol.
As a result of all this, doctors don’t just want you to lower your total cholesterol count; they want you to change the ratio as well, so you have more HDL and less LDL. “When we looked at the data, we found that the higher your HDL went, the lower your risk of heart attack,” says cardiologist William Castelli, M.D., former director of the Framingham Heart Study in Massachusetts. An HDL level of 75 or more seems to convey extra longevity for many people, while a count of 100 or more is so beneficial that it was dubbed the “Methuselah syndrome” by one researcher. HDL less than 35 or so, meanwhile, can carry significant risk of heart disease. Genetics plays a large role in HDL. A few guys have naturally low levels and need to keep their LDL low as well to make up for it. (As Castelli puts it, you don’t need a substance that removes cholesterol from your blood if you don’t have much to begin with.) But there’s plenty that everyone else can do to pump up their HDL. Never one to shirk from a task that doesn’t involve housecleaning, I managed to find two handfuls of ways to turn my “good” numbers into great numbers.