Fruits and vegetables exert a substantial thermogenic effect because carbohydrate in general is moderately thermogenic, and fiber is highly thermogenic.
Thermogenic ( To produce heat in the fat burning process.)
However, some fruits and vegetables are more carbohydrate-dense than others. For example, potatoes are thermogenic and so are bananas, but they also contain more active carbohydrate than do apples or strawberries.
Stated differently, apples and strawberries are more thermogenic per unit of carbohydrate. Cruciferous vegetables like broccoli and cauliflower are so thermogenic per unit of carbohydrate that they do not count toward your daily carbohydrate limit.
– Everyone knows that broccoli has relatively few total calories, but, in view of its strong thermogenic effect, broccoli has even fewer actual calories.
You will want to eat carbohydrate foods that have high thermogenic per unit of carbohydrate. This will allow you to consume a greater volume of food than if you were eating foods of a higher carbohydrate density. A greater volume of food is positively correlated not only with metabolic rate but also with satiety. Food volume is important in appetite regulation, because gastric distention and intestinal stimulation send “I’m full” signal to your brain.
Many breakfast cereals, for example, are high in fiber, but have a low thermogenic/carbohydrate ratio. You are limited in how much of such foods you can eat, and bird-like portions are neither satisfying nor significantly increase metabolic rate.
High-fiber/high-water-content (HIFWAC) fruits and non-starchy vegetables are ideal for optimizing thermogenesis.
Conversely, consuming carbohydrate foods low in water and fiber will force you to miniaturize your portion sizes in order to stay within carb limits. HIFWAC fruits are less carbohydrate-dense, and thus have greater thermogenic value per unit of carbohydrate than do other fruits.
(Excellent Thermogenic/Carbohydrate Ratio)
Apples, Apricots, Blueberries, Cherries, Grapes, Peaches, Pears, Raspberries, Strawberries
Non-HIFW AC Fruits
(Inferior Thermogenic/Carbohydrate Ratio)
Bananas, Dates, Dried Fruit, Figs, Raisins, Watermelon
An easy way to identify which carbohydrate foods have high thermogenic value per unit of carbohydrate is to assess “active carbs”. The lower the active carb rating of a particular carbohydrate food, the more thermogenic that food is per unit of carbohydrate.
The reason for this correspondence is that, by calculating active carbs, you are subtracting fiber (the non-caloric thermogenic element) from total carbohydrate. Accordingly, active carbs can be viewed as a measure of how “unthermogenic” a food is per unit of carbohydrate. .
Lower Active Carb Content = More Thermogenic Per Unit of Carbohydrate = Greater Volume Per Unit of Carbohydrate
To illustrate how widely foods vary in volume and thermogenic potency per unit of carbohydrate, consider that in terms of active carbohydrate:
Asparagus Broccoli Cabbage Cauliflower Celery Lettuce Mushroom Radicchio Radish Spinach
If these vegetables don’t strike you as being among the most appetizing foods you’ve ever eaten, remember, melted butter or melted cheese can do wonders for the taste. And both of these toppings are permissible in moderate quantities.
Furthermore, you will notice from the list that you have the makings of a tasty salad; and since you are allowed to consume fat in moderation, feta cheese, sunflower seeds, and rich dressings are all possibilities. One word of caution, though: many dressings contain more carbohydrate than you might imagine. Be sure to account for the carbohydrate content of the dressing and the croutons if there are any.
By switching from a carbohydrate-based diet to a protein-based diet, you automatically increase thermogenesis.
There are two exceptions to the rule that protein foods are the most highly thermogenic:
1) protein foods that are high in fat (fat has low thermogenic value) and
2) protein foods that have been processed. A classic example of a highly processed protein food is protein powder. Lunch meats, too, are processed; and have lower thermogenic value than fresh, cooked meat (and they are inferior to fresh meat in all other nutritional respects as well; so don’t rely on lunch meats as your primary protein source.)
In addition to being powerfully thermogenic, meat is an excellent food in terms of its nutritional content. If you are a vegetarian, tofu and other soy-based products are fine substitutes for meat. Soy protein, having been found to improve cholesterol.
When preparing meat, take reasonable measures, like draining grease, to avoid excess fat. It is not necessary, however, to surgically remove all visible fat, a practice common among low-fat devotees. Along the same line, make sure that most of the meat you consume contains more protein than fat. Sausage and bacon are fine every once in a while, but stick to lean meat most of the time.